On the moulding of population viscosity by natural selection

In this paper, we explore the conjoint evolution of dispersal and social behaviour. The model investigated is of a population distributed over a number of sites each with a carrying capacity of two adults and an episode of dispersal in the juvenile stage. The fertilities are governed by whether an individual and its neighbour are selfish or co-operative. It is shown that the best dispersal strategy for the co-operative genotype always involves lower levels of dispersal; and further that ecological conditions favouring low levels of dispersal increase the selective advantage of a co-operative genotype. Given this positive feedback, we suggest that in any taxon viscosity and co-operativity will tend to be correlated and bimodally distributed. Hence we predict the existence of two kinds of animal societies; viscous and co-operative (e.g. quasi-social wasps such as Mischocyttarus), and non-viscous and selfish (e.g. communal sphecid wasps such as Cerceris), and relatively few social groups with intermediate levels of co-operativity and viscosity. We also suggest that when one of the two sexes disperses, it will be the sex with lower potential for co-operative behaviour.

Non-melanoma skin cancer: Ten years of cancer-registry-based surveillance

The Tasmanian Cancer Registry carried out population-based surveillance of non-melanoma skin cancer (NMSC) from 1978 to 1987. A total of 8,651 NMSC were recorded in 7,160 individuals, representing an age-standardized rate of 161/100,000 per year. Ninety-four percent of cases were based on histological diagnosis. Incidence of basal-cell carcinoma (BCC) was higher than the incidence of squamous-cell carcinoma (SCC). The incidence of NMSC was twice as high in men as in women. Incidence increased substantially with age, more markedly for SCC than BCC. For most body sites, BCC was more frequent, but on highly exposed sites such as the backs of hands, lower limbs in women and ears in men, the incidence of SCC was higher. There was an overall increase of 7% per year in the age-standardized incidence rate of NMSC. The increase was more marked for BCC than for SCC, and was consistent across age groups and both sexes. A first NMSC during the study period was associated with a 12-fold increase among men and a 15-fold increase among women in the risk of development of a new NMSC within 5 years, when compared with the NMSC incidence recorded for the population as a whole.

Kansanomainen moraali : Tutkimus savolaisista ja pohjalaisista uskomustarinoista

In my research I discuss belief legends as representations of folk morals. Doing wrong is not one s private affair because it can have consequences for the life of a whole community, and therefore, it is in a community s interest to control the conduct of its members. Belief legends have served as a means of instruction for proper behaviour. In this way a community has contributed to the socialization of its members so as to make them comply with common norms and morals. My study is focused on belief legends relating to some type of offence (a crime, an infringement or another kind of misdeed) and its consequences. I try to find out whether there are regional differences and similarities. The material consists of 3120 warning legends that have been recorded in the years 1881‒1981, mainly in Southern Savo and Southern Ostrobothnia, partly in Northern Savo and Northern Ostrobothnia. I have collected the material at the Folklore Archives of the Finnish Literature Society. As a research method I apply discourse analysis to outline the schematic model of the legends, the superstructure, and the substance of the legends, the semantic macrostructure. Also I apply quantitative methods such as cross tabulations in order to establish regional differences and similarities in the concentrated and far abstracted semantic macrostructure of the legends. I look for explanations for the perceptions made in, above all, the cultural context but also with the view of the development of judicial history. Warning legends relating to what is wrong or right are clearly an expression of peasant folklore. The most common types of offences are violations of law and transgressions of Christian traditions and of social conduct. Transgression of Christian traditions is the most frequently committed offence in all geographical areas surveyed. Warning legends have an explicit focus on offence committed by a single person. The most common punishing figure in Southern Savo is the Devil, in Southern Ostrobothnia the Dead, in Northern Savo God, and in Northern Ostrobothnia the Dead or God. The most rigid folk morals are manifested in legends from Northern Savo, where narratives of mortal sin are more frequent than in other areas. The influence of the revivalist movements may be alleged in explanation of this phenomenon. According to these legends people living in Southern Savo are the most tolerant of those included in the study, presumably because of a more liberal revivalist movement in this area, called the Friendship movement. In folk morals women are treated more severely than men. Characteristic of the legends from Ostrobothnia is the emphasis on community, while the legends from Savo lay stress on individuality. The legends from Ostrobothnia manifest a more explicit distinction between the offence committed by a woman and one committed by a man than do legends from Savo. An explanation may be found in the prevailing industries, adherent in the division of labour between the sexes, in this region. The legends are man-centric. Women s occupations are connected with home and family, whereas men s fields of activities are wider. Women moralise each other harsher than do men. Folk morals advise people to be moderate in every sense. Through belief legends people are taught to respect human beings and the rest of creation, to obey the Christian religion and God, and to be moderate in search of wealth.

Host recognition by a polyphagous lepidopteran (Helicoverpa armigera): Primary host plants, host produced volatiles and neurosensory stimulation

An important question in the host-finding behaviour of a polyphagous insect is whether the insect recognizes a suite or template of chemicals that are common to many plants? To answer this question, headspace volatiles of a subset of commonly used host plants (pigeon pea, tobacco, cotton and bean) and nonhost plants (lantana and oleander) of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) are screened by gas chromatography (GC) linked to a mated female H. armigera electroantennograph (EAG). In the present study, pigeon pea is postulated to be a primary host plant of the insect, for comparison of the EAG responses across the test plants. EAG responses for pigeon pea volatiles are also compared between females of different physiological status (virgin and mated females) and the sexes. Eight electrophysiologically active compounds in pigeon pea headspace are identified in relatively high concentrations using GC linked to mass spectrometry (GC-MS). These comprised three green leaf volatiles [(2E)-hexenal, (3Z)-hexenylacetate and (3Z)-hexenyl-2-methylbutyrate] and five monoterpenes (α-pinene, β-myrcene, limonene, E-β-ocimene and linalool). Other tested host plants have a smaller subset of these electrophysiologically active compounds and even the nonhost plants contain some of these compounds, all at relatively lower concentrations than pigeon pea. The physiological status or sex of the moths has no effect on the responses for these identified compounds. The present study demonstrates how some host plants can be primary targets for moths that are searching for hosts whereas the other host plants are incidental or secondary targets.

Systematics: A new fossil genus of small-headed flies (Diptera: Acroceridae: Philopotinae) from Baltic amber

A new genus of philopotine Acroceridae in Baltic amber is described from both sexes. Archaeterphis hennigi gen. et sp. nov. is easily diagnosed from all other acrocerid genera by the deeply emarginate hind margin of the eye, short mouthparts, reduced wing venation, modified hind femora, and the large postpronotal lobes being proximate but not touching. The new genus is closely related to the extant genus Africaterphis Schlinger from southern Africa, which accords with a common biogeographic pattern in insects.

Genetics of heifer performance in 'wet' and 'dry' seasons and their relationships with steer performance in two tropical beef genotypes.

The genetics of heifer performance in tropical 'wet' and 'dry' seasons, and relationships with steer performance, were studied in Brahman (BRAH) and Tropical Composite (TCOMP) (50% Bos indicus, African Sanga or other tropically adapted Bos taurus; 50% non-tropically adapted Bos taurus) cattle of northern Australia. Data were from 2159 heifers (1027 BRAH, 1132 TCOMP), representing 54 BRAH and 51 TCOMP sires. Heifers were assessed after post-weaning 'wet' (ENDWET) and 'dry' (ENDDRY) seasons. Steers were assessed post-weaning, at feedlot entry, over a 70-day feed test, and after similar to 120-day finishing. Measures studied in both heifers and steers were liveweight (LWT), scanned rump fat, rib fat and M. longissimus area (SEMA), body condition score (CS), hip height (HH), serum insulin-like growth factor-I concentration (IGF-I), and average daily gains (ADG). Additional steer measures were scanned intra-muscular fat%, flight time, and daily (DFI) and residual feed intake (RFI). Uni- and bivariate analyses were conducted for combined genotypes and for individual genotypes. Genotype means were predicted for a subset of data involving 34 BRAH and 26 TCOMP sires. A meta-analysis of genetic correlation estimates examined how these were related to the difference between measurement environments for specific traits. There were genotype differences at the level of means, variances and genetic correlations. BRAH heifers were significantly (P < 0.05) faster-growing in the 'wet' season, slower-growing in the 'dry' season, lighter at ENDDRY, and taller and fatter with greater CS and IGF-I at both ENDWET and ENDDRY. Heritabilities were generally in the 20 to 60% range for both genotypes. Phenotypic and genetic variances, and genetic correlations, were commonly lower for BRAH. Differences were often explained by the long period of tropical adaptation of B. indicus. Genetic correlations were high between corresponding measures at ENDWET and ENDDRY, positive between fat and muscle measures in TCOMP but negative in BRAH (mean of 13 estimates 0.50 and -0.19, respectively), and approximately zero between steer feedlot ADG and heifer ADG in BRAH. Numerous genetic correlations between heifers and steers differed substantially from unity, especially in BRAH, suggesting there may be scope to select differently in the sexes where that would aid the differing roles of heifers and steers in production. Genetic correlations declined as measurement environments became more different, the rates of decline (environment sensitivity) sometimes differing with genotype. Similar measures (LWT, HH and ADG; IGF-I at ENDWET in TCOMP) were genetically correlated with steer DFI in heifers as in steers. Heifer SEMA was genetically correlated with steer feedlot RFI in BRAH (0.75 +/- 0.27 at ENDWET, 0.66 +/- 0.24 at ENDDRY). Selection to reduce steer RFI would reduce SEMA in BRAH heifers but otherwise have only small effects on heifers before their first joining.

Ravintoa keholle, ruokaa mielelle : vertailututkimus pohjoismaisten nuorten ruokatottumuksista kotona ja koulussa

Aims. The main meals that youngsters have during the day are eaten at home and at school. In the Nordic countries breakfast and supper are often eaten with other members of the family. The way that Nordic countries arrange the school lunch and the frequency of family meals differ between countries. However, the challenges related to eating habits of the young are surprisingly similar. The aim of this study is to discuss how the Nordic countries could support youngsters’ healthy eating habits. This study was carried out as a part of a Nordic research project and it completed the work done by Kauppinen (2009) and Niemi (2009) in their Master’s Theses. The research questions are: 1. How do the youngsters evaluate their own eating habits and those of their family? 2. How do the youngsters evaluate the influence of home, family and school on their own eating habits? 3. What kind of relationship exists between eating at home and at school according to the data? Data and methods. A quantitative internet-based survey was used to collect data (N=1539) on the 9th graders conceptions and understandings. The survey consisted of respondents from Finland (N=586), Sweden (N=427), Denmark (N=295) and Norway (N=246). In this study the whole data to the appropriate extent was analyzed. The analysis was done with the SPSS-software and included examination of means, standard deviations, cross-tabulations, Pearson´s correlations, Chi-squared -tests, t-tests and one-way analysis of variance (ANOVA). The results were compaired between the countries and between sexes. Results and discussion. The studied youngsters evaluated their own eating habits positively. There were statistically signifigant differences (p< .05) between countries concerning the people who influence the youngsters’ healthy eating habits. Youngsters from Finland and Sweden considered making healthy choices at school easier than those from Denmark and Norway. Also eating a so called healthy lunch at school was more common in Finland and in Sweden. Eating breakfast and eating a healthy meal at school had a statistically significant interconnection (p< .001). The differences between sexes were not equal between the countries. The results supported those from previous studies, but also raised ideas for further study. Youngsters’ near environments should support their possibilities to make healthy choices and to participate to the decicion making process. Co-operation between the Nordic countries and between the home and the school is important. Listening to the youngsters’ own voice is a challence and a possibility for developing both home economics education and research in this area. Key words: Nordic countries, youngsters, healthy eating habits, eating at home, school meals

Kivaa ja hyödyllistä, mutta jo se riittää : Yläasteen kielikylpyoppilaiden käsityksiä ruotsinkielisestä kielikylpyopetuksesta Helsingissä

The aim of this study was to find out how immersion students experience immersion education, how they feel about the implementation of immersion education methods and what role immersion plays in immersion students’ lives outside the school context. In addition, the influence of sex, grade level, school and type of immersion education on students’ perceptions was studied. The population included all students at the lower secondary level in Helsinki who participated in Swedish immersion education during 2002–2003. The sample consisted of 128 students who represented two different forms of immersion: 47% of the students had previously participated in early total immersion while 53 % of the students had taken part in early partial immersion. The data were gathered through a questionnaire and interviews. All 128 students answered the questionnaire, and 10 students were chosen to focus interviews through purposive sampling. In addition, students’ parents were invited to fill in a questionnaire where students’ background information was requested. The data were collected during the spring of 2003. Principal Component Analysis and one-way variance analysis were used as statistical analysis methods. Also frequencies, average, correlations and cross tabs were studied. In the PCA a right-angled varimax-rotation was performed separately to every thematic entity that arose from the theoretical background. Sum variables were formed from the Principal Components by summing up all the items that received over .400 charges for the specific Principal Component. Significance testing of the mean was performed with F and t-tests. Results indicate that immersion students in lower secondary school experience immersion quite diversely as a whole. Students are satisfied with the fact that they are in the immersion class but not with the amount of teaching in Swedish. Students feel it is very important and useful to learn Swedish bearing in mind their future studies and working life. The students estimate their language skills to be very high. Yet they prefer using Finnish during classes. The fact that teachers use Swedish does not considerably affect how well the students learn the factual content in various subjects, especially if the student knows Swedish well. Theoretical subjects seemed to cause most problems. Swedish played only a very small part in students’ lives outside the school context and it was used merely when travelling abroad and in different kinds of guiding situations. Unless the students were talked to in Swedish, they kept on speaking Finnish. When asked about students’ experiences no statistically significant differences between sexes were found in this study. On the contrary, in some cases their grade level but especially their school and form of immersion had clear statistically significant differences on students’ perceptions.

Development of a synthetic plant volatile-based attracticide for female noctuid moths. I. Potential sources of volatiles attractive to Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae).

This paper is the first of a series which will describe the development of a synthetic plant volatile-based attracticide for noctuid moths. It discusses potential sources of volatiles attractive to the cotton bollworm, Helicoverpa armigera (Hubner), and an approach to the combination of these volatiles in synthetic blends. We screened a number of known host and non-host (for larval development) plants for attractiveness to unmated male and female moths of this species, using a two-choice olfactometer system. Out of 38 plants tested, 33 were significantly attractive to both sexes. There was a strong correlation between attractiveness of plants to males and females. The Australian natives, Angophora floribunda and several Eucalyptus species were the most attractive plants. These plants have not been recorded either as larval or oviposition hosts of Helicoverpa spp., suggesting that attraction in the olfactometer might have been as nectar foraging rather than as oviposition sources. To identify potential compounds that might be useful in developing moth attractants, especially for females, collections of volatiles were made from plants that were attractive to moths in the olfactometer. Green leaf volatiles, floral volatiles, aromatic compounds, monoterpenes and sesquiterpenes were found. We propose an approach to developing synthetic attractants, here termed 'super-blending', in which compounds from all these classes, which are in common between attractive plants, might be combined in blends which do not mimic any particular attractive plant.

Nutritional intake of opioid replacement therapy patients in community pharmacies: A pilot study

Aim: Opioid replacement therapy (ORT) is an established therapy for a patient group that has been associated with nutrition-related comorbidities. This paper aims to assess the nutritional intake and supplementation in ORT patients, determine the extent of nutritional/dietary advice supplied to ORT patients and to briefly examine patients' perception of pharmacists' provision of nutritional advice. Methods: The nutritional intake of ORT patients receiving treatment in community pharmacies within the Australian Capital Territory was assessed via a 24-hour recall survey. Food intake data were analysed via nutrient analysis software and compared with Australian Nutrition Reference Values and the nutrient intakes of the Australian population. Patients were surveyed to determine supplement use and perceptions of nutritional advice gained by pharmacists. Results: Potential insufficient intake of various macronutrients and micronutrients was observed in both sexes. Less than 25 of patients recorded supplement use. Fifteen percent of males and 21 of females stated that they had approached a pharmacist with a nutrition-related query. All patients who received nutritional advice followed the advice. Conclusions: ORT patients dosing at community pharmacies appear to have poor nutritional intake. ORT patients appear to be receptive to pharmacist's advice. Community pharmacists can potentially increase the beneficial health outcomes in this population through the proactive supply of accurate nutritional advice.

Sex Determination - A Hypothesis Based On Noncoding Dna

Certain recent models of sex determination in mammals, Drosophila melanogaster, Caenorhabditis elegans, and snakes are examined in the light of the hypothesis that the relevant genetic regulatory mechanisms are similar and interrelated. The proposed key element in each of these instances is a noncoding DNA sequence, which serves as a high-affinity binding site for a repressor-like molecule regulating the activity of a major "sex-determining" gene. On this basis it is argued that, in several eukaryotes, (i) certain DNA sequences that are sex-determining are noncoding, in the sense that they are not the structural genes of a sex-determining protein; (ii) in some species these noncoding sequences are present in one sex and absent in the other, while in others their copy number or accessibility to regulatory molecules is significantly unequal between the two sexes; and (iii) this inequality determines whether the embryo develops into a male or a female.

Young Men s Sexual Behaviour in Finland and Estonia : Opportunities for prevention of sexually transmitted infections

Background: The incidence of sexually transmitted infections (STIs) in most EU states has gradually increased and the rate of newly diagnosed HIV cases has doubled since 1999. STIs differ in their clinical features, prognosis and transmission dynamics, though they do share a common factor in their mode of transmission −that is, human behaviour. The evolvement of STI epidemiology involves a joint action of biological, epidemiological and societal factors. Of the more immediate factors, besides timely diagnosis and appropriate treatment, STI incidence is influenced by population patterns of sexual risk behaviour, particularly the number of sexual partners and the frequency of unprotected intercourse. Assessment of sexual behaviour, its sociodemographic determinants and time-trends are important in understanding the distribution and dynamic of STI epidemiology. Additionally, in the light of the basic structural determinants, such as increased level of migration, changes in gender dynamics and impacts from globalization, with its increasing alignment of values and beliefs, can reveal future challenges related to STI epidemiology. STI case surveillance together with surveillance on sexual behaviour can guide the identification of preventive strategies, assess their effectiveness and predict emerging trends. The objective of this study was to provide base line data on sexual risk behaviour, self-reported STIs and their patterns by sociodemographic factors as well as associations of sexual risk behaviour with substance use among young men in Finland and Estonia. In Finland national population based data on adult men s sexual behaviour is limited. The findings are discussed in the context of STI epidemiology as well as their possible implications for public health policies and prevention strategies. Materials and Methods: Data from three different cross-sectional population-based surveys conducted in Finland and Estonia, during 1998 2005, were used. Sexual behaviour- and health-related questions were incorporated in two surveys in Finland; the Health 2000, a large scale general health survey, focussed on young adults, and the Military health behavioural survey on military conscripts participating in the mandatory military training. Through research collaboration with Estonia, similar questions to the Finnish surveys were introduced to the second Estonian HIV/AIDS survey, which was targeted at young adults. All surveys applied mail-returned, anonymous, self-administered questionnaires with multiple choice formatted answers. Results: In Finland, differences in sexual behaviour between young men and women were minor. An age-stratified analysis revealed that the sex-related difference observed in the youngest age group (18 19 years) levelled off in the age group 20 24 and almost disappeared among those aged 25 29. Marital status was the most important sociodemographic correlate for sexual behaviour for both sexes, singles reporting higher numbers of lifetime-partners and condom use. This effect was stronger for women than for men. However, of those who had sex with casual partners, 15% were married or co-habiting, with no difference between male and female respondents. According to the Military health behavioural survey, young men s sexual risk behaviour in Finland did not markedly change over a period of time between 1998 and 2005. Approximately 30−40% of young men had had multiple sex partners (more than five) in their lifetime, over 20% reported having had multiple sex partners (at least three) over the past year and 50% did not use a condom in their last sexual intercourse. Some 10% of men reported accumulation of risk factors, i.e. having had both, multiple sex partners and not used a condom in their last intercourse, over the past year of the survey. When differences and similarities were viewed within Finland and Estonia, a clear sociodemographic patterning of sexual risk behaviour and self-reported STIs was found in Finland, but a somewhat less consistent trend in Estonia. Generally, both, alcohol and drug use were strong correlates for sexual risk behaviour and self-reported STIs in Finland and Estonia, having a greater effect on engagement with multiple sex partners rather than unprotected intercourse or self-reported STIs. In Finland alcohol use, relative to drug use, was a stronger predictor of sexual risk behaviour and self-reported STIs, while in Estonia drug use predicted sexual risk behaviour and self-reported STIs stronger than alcohol use. Conclusions: The study results point to the importance for prevention of sexual risk behaviour, particularly strategies that integrate sexual risk with alcohol and drug use risks. The results point to the need to focus further research on sexual behaviour and STIs among young people; on tracking trends among general population as well as applying in-depth research to identify and learn from vulnerable and high-risk population groups for STIs who are exposed to a combination of risk factors.

Coffee and risk of type 2 diabetes

Type 2 diabetes is one of the diseases that largely determined by lifestyle factors. Coffee is one of the most consumed beverages in the world and recently released data suggest the effects of coffee consumption on type 2 diabetes. The objective of the present study was to evaluate the effects of habitual coffee consumption on various aspects of type 2 diabetes and its most common complications. This study is part of the national FINRISK studies. Baseline surveys were carried out between 1972 and 1997. The surveys covered two eastern regions in 1972 and 1977, but were expanded to include a third region in southwestern Finland in 1982, 1987, 1992, and 1997. The Helsinki capital area was included in the survey in 1992 and 1997 and the Oulu province, in northern Finland, in 1997. Each survey was drawn from an independent random sample of the national register of subjects aged 25-64. In 1997, an additional sample of subjects aged 65-74 was conducted. The blood pressure, weight, and height of subjects were measured. By using self-administered questionnaires data were collected on medical history, socioeconomic factors, physical activity, smoking habits, and alcohol, coffee, and tea consumption. Higher coffee consumption was associated with higher body mass index, occupational physical activity and cigarette smoking, and lower blood pressure, education level, leisure time physical activity, tea consumption and alcohol use. Age, body mass index, systolic blood pressure and current smoking were positively associated with the risk of type 2 diabetes, however, education, and occupational, commuting and leisure time physical activity were inversely associated. The significant inverse association between coffee consumption and the risk of type 2 diabetes was found in both sexes but the association was stronger in women. Coffee consumption was significantly and inversely associated with fasting glucose, 2-hour plasma glucose, fasting insulin, impaired fasting glucose, impaired glucose regulation, and hyperinsulinemia among both men and women and with isolated impaired glucose tolerance among women. Serum gamma-glutamyltransferase modified the association between coffee consumption and incident diabetes. Among subjects with high serum -glutamyltransferase (>75th percentile), coffee consumption showed an inverse association for women, as well as men and women combined. An inverse association also occurred between coffee consumption and the risk of total, cardiovascular disease, and coronary heart disease mortality among patients with type 2 diabetes. The results of this study showed that habitual coffee consumption may be associated with a reduced risk of type 2 diabetes. Coffee consumption may have some effects on several markers of glycemia, and may lower the incident of type 2 diabetes in high normal serum -glutamyltransferase levels. Total, cardiovascular disease, and coronary heart disease mortality rate among subjects with type 2 diabetes may also be reduced by coffee consumption.

Obesity, Smoking and Dieting

Lihavuus ja ylipaino ovat viime vuosikymmeninä yleistyneet; jo yli puolet länsimaiden väestöstä on ylipainoisia ja viidennes lihavia. Varsinkin nuorilla ylipainon lisääntyminen on ollut nopeaa. Ylipaino, erityisesti yhdistettynä vyötärölihavuuteen, sekä tupakointi lisäävät sairastavuutta sydän- ja verisuonisairauksiin, metabolisiin sairauksiin, kuten diabetekseen, sekä moniin syöpiin. Lihavuus ja tupakointi ovatkin kehittyneiden maiden tärkeimpiä ehkäistävissä olevia kuolinsyitä. Samanaikaisesti ylipainon kanssa laihduttaminen ja jopa terveydelle haitalliset laihdutusmenetelmät, kuten tupakointi painonhallintakeinona on tullut yhä yleisemmäksi. Nopeaan painonpudotukseen tähtäävällä laihduttamisella on usein terveydelle haitallisia seurauksia kuten painon nousu yli alkuperäisen painon ja kehon rasvajakauman muuttuminen epäterveellisemmäksi. Kolme neljännestä merkittävästi laihduttaneista kertoo painon nousseen takaisin. Tupakoinnin ja toistuvan laihduttamisen vaikutukset ylipainon ja lihavuuden kehittymiselle kytkeytyvät toisiinsa. Tässä väitöskirjatyössä tutkittiin toistuvan laihduttamisen ja tupakoinnin vaikutusta kehon painoon ja lisäksi tupakoinnin vaikutusta vyötärölihavuuden kehittymiseen. Työn toisena tavoitteena oli tutkia, kuinka voimakkaasti tupakointi ja toistuva laihduttaminen liittyvät toisiinsa suomalaisilla ja onko tämä yhteys erilainen eri ikäryhmissä ja sukupuolilla. Työ perustuu kolmeen laajaan kyselyaineistoon: Nuorten Kaksosten Terveystutkimuksen (englanniksi FinnTwin16) aineistossa on seurattu 1975-79 syntyneitä kaksosia 16, 17, 18 ja 24 vuoden ikäisinä (N=5563). Suomen kaksoskohortin aineisto (N= 12 793) on kerätty vuonna 1990 samaa sukupuolta olevilta, vuosina 1930-57 syntyneiltä kaksosilta. Entisten huippu-urheilijoiden (N=1838) ja heille kaltaistettujen verrokkien (N=834) seurantatutkimuksessa tiedot on kerätty vuosina 1985, 1995 ja 2001. Pituus, paino ja tupakointi on kysytty kaikissa kyselyissä. Kaksoset vastasivat laihdutuskäyttäytymistä koskeviin kysymyksiin. Urheilijoiden laihdutuskäyttäytyminen pääteltiin lajin perusteella, sillä toistuvan laihduttamisen tiedetään olevan yleistä painoluokissa urheilevilla urheilijoilla (esim.painijat, nyrkkeilijät). Nuoruusiän tupakointi ennusti vyötärölihavuutta molemmilla sukupuolilla ja lisäksi ylipainoisuutta naisilla. Toistuva laihduttaminen oli yhteydessä myöhempään painonnousuun ja lihavuuteen miehillä. Lisäksi toistuvan laihduttamisen ja tupakoinnin todettiin liittyvän toisiinsa nuorilla aikuisilla. Vanhemmissa ikäluokissa miehet, jotka tupakoivat, laihduttivat harvemmin kuin tupakoimattomat. Lihavuuteen ja vyötärölihavuuteen liittyvän oheissairastavuuden ennaltaehkäisyssä tupakoinnin ja toistuvan laihduttamisen vähentäminen saattavat olla aiemmin luultua tehokkaampia keinoja.

Male eating disorders and related traits : Genetic epidemiological study in Finnish twins

The aim of this study was to deepen the understanding of eating disorders, body image dissatisfaction and related traits in males by examining the epidemiology and genetic epidemiology of these conditions in representative population-based twin samples. The sample of Study I included adolescent twins from FinnTwin12 cohorts born 1983 87 and assessed by a questionnaire at ages 14 y (N=2070 boys, N=2062 girls) and 17 y (N=1857 boys, N=1984 girls). Samples of Studies II-V consisted of young adult twins born 1974-79 from FinnTwin16 cohorts (Study II N=1245 men, Study III N=724 men, Study IV N=2122 men, Study V N=2426 women and N=1962 men), who were assessed by a questionnaire at the age 22-28 y. In addition, 49 men and 526 women were assessed by a diagnostic interview. The overall response rates for both twin cohorts in all studies were 80-90%. In boys, mainly genetic factors (82%, 95% confidence interval [CI] 72-92) explained the covariation of self-esteem between the ages 14 y and 17 y, whereas in girls, environmental factors (69%, 95% CI 43-93) were the largest contributors. Of young men, 30% experienced high muscle dissatisfaction, while 12% used or had used muscle building supplements and/or anabolic steroids on a regular basis. Muscle dissatisfaction exhibited a robust association with the indicators of mental distress and a genetic component (42%, 95% CI 23-59) for its liability in this population was found. The variation of muscle-building substance use was primarily explained by the environmental factors. The incidence rate of anorexia nervosa in males for the age of 10-24 y was 15.7 (95% CI 6.6-37.8) per 100 000 person-years, and its lifetime prevalence by the young adulthood was 0.24% (95% CI 0.03-0.44). All detected probands with anorexia nervosa had recovered from eating disorders, but suffered from substantial psychiatric comorbidity, which manifested also in their co-twins. Additionally, male co-twins of the probands displayed significant dissatisfaction with body musculature, a male-specific feature of body dysmorphic disorder. All probands were from twin pairs discordant for eating disorders. Of the five male probands with anorexia nervosa, only one was from an opposite-sex twin pair. Among women from the opposite-sex pairs, the prevalence of DSM-IV or broad anorexia nervosa was no significantly different compared to that of the women from monozygotic pairs or from dizygotic same-sex pairs. The prevalence of DSM-IV or broad bulimia nervosa did not differ in opposite- versus same-sex female twin individuals either. In both sexes, the overall profile of indicators on eating disorders was rather similar between individuals from opposite-sex and same-sex pairs. In adolescence, development of self-esteem was differently regulated in boys compared to girls: this finding may have far-reaching implications on the etiology of sex discrepancy of internalizing and externalizing disorders. In young men, muscle dissatisfaction and muscle building supplement/steroid use were relatively common. Muscle dissatisfaction was associated with marked psychological distress such as symptoms of depression and disordered eating. Both genetic and environmental factors explained muscle dissatisfaction in the population, but environmental factors appeared to best explain the use of muscle-building substances. In this study, anorexia nervosa in boys and young men from the general population was more common, transient and accompanied by more substantial co-morbidity than previously thought. Co-twins of the probands with anorexia nervosa displayed significant psychopathology such as male specific symptoms of body dysmorphic disorder, but none of them had had an eating disorder: taken together, these traits are suggestive for an endophenotype of anorexia nervosa in males. Little evidence was found on that the risk for anorexia nervosa, bulimia nervosa, disordered eating or body dissatisfaction were associated with twin zygosity. Thus, it is unlikely that in utero femininization, masculinization or postnatal socialization according to the sex of the co-twin have a major influence on the later development of eating disorders or related traits.