Markers and risk factors for HCV, HBV and HIV in a network of injecting drug users in Melbourne

Background and aims: Current injecting drug users (IDU) in major street drug markets within greater Melbourne were recruited to a longitudinal study on blood borne viruses. Here we investigated risk factors for hepatitis C virus (HCV), hepatitis B virus (HBV) and HIV infection in these IDU at the time of their recruitment.

Methods : Three hundred and eighty-two IDU completed detailed questionnaires on their drug use and risk behaviours, and provided blood samples for serology testing. These data were analysed using univariate and multivariate techniques.

Results : The overall prevalence of exposure to HCV, HBV and HIV was estimated at 70%, 34% and <1%, respectively. Independent predictors of HCV exposure were history of imprisonment (RR 1.34, 95% CI 1.19–1.52), use of someone else's needle or syringe (RR 1.23, 95% CI 1.07–1.42), >7.6 years length of time injecting (RR 1.21, 95% CI 1.07–1.37), and originating from Vietnam (RR 1.12, 95% CI 1.07–1.18). Independent predictors of HBV exposure were HCV exposure (RR 2.15, 95% CI 1.35–3.43), >7.6 years length of time injecting (RR 1.57, 95% CI 1.17–2.13) and originating from outside Australia (RR 1.60, 95% CI 1.22–2.10). Neither prison- nor community-applied tattoos predicted HCV or HBV exposure. Up to 31% of IDU who injected for 1 year or less were HCV antibody positive, as were 53% of those who injected for 2 years or less.

Conclusions : Ongoing engagement with young IDU, through the provision of harm reduction education and resources, is critical if we are to address blood borne viral infections and other health and social harms associated with injecting drug use.

Hepatitis C virus infection in South Australian prisoners : seroprevalence, seroconversion, and risk factors

Objectives : To determine entry antibody seroprevalence and seroconversion to hepatitis C virus (HCV) and associated risk factors in newly incarcerated prisoners.

Methods : Males and females entering South Australian prisons completed risk factor surveys and were offered HCV-antibody testing. Participants completed additional surveys and, if HCV-negative at last test, underwent further antibody tests at 3-monthly intervals for up to 15 months. Data were analyzed using univariate and multivariate techniques.

Results : HCV seroprevalence among 662 prison entrants was estimated at 42%. Previous injecting history was highly prevalent at entry (64%) and both community and prison injecting independently predicted entry HCV status. Tattooing was not an important risk factor. While community exposure could not be ruled out, three seroconversions were noted in 148 initially HCV-seronegative individuals occurring in a median 121 days – 4.6 per 100 person-years. Prison injecting was infrequently reported, but HCV-seropositive participants were significantly more likely to commence IDU in prison than seronegative participants (p = 0.035).

Conclusions : Entry HCV seroprevalence in South Australian prisoners is extremely high and may have contributed to a ‘ceiling effect’, minimizing the observable seroconversion rate. Greater frequency of injecting among those already infected with HCV represents a significant threat to other prisoners and prison staff.

Anthropometric risk factors for patellar tendon injury among volleyball players

Objective: Abnormal imaging in the patellar tendon reveals pathology that is often associated with knee pain. Anthropometric measures of body size and mass, such as height, weight and waist-to-hip ratio (WHR), have been individually associated with abnormal imaging. The aim of this study was to investigate the anthropometric factors that have the strongest relationship with abnormal imaging in volleyball players.

Methods: Height, weight, body mass index (BMI), waist girth, hip girth and WHR were measured in a cohort of 113 competitive volleyball players (73 men, 40 women). The univariate (ANOVA) and multivariable (discriminant function analysis) association between abnormal imaging and these anthropometric factors were investigated.

Results: No significant association was found in the female volleyball players. A significant univariate association was observed between abnormal imaging and heavier weight, greater BMI, larger waist and hip girth and larger WHR in the male volleyball players. Waist girth was the only factor that retained this association in a multivariable model (p<0.05).

Conclusions: Men with a waist girth greater than 83 cm seem to be at greater risk of developing patellar tendon pathology. There may be both mechanical and biochemical reasons for this increased risk.

Validation of model-based estimates (synthetic estimates) of the prevalence of risk factors for coronary heart disease for wards in England

Several sets of model-based estimates (synthetic estimates) of the prevalence of risk factors for coronary heart disease for small areas in England have been developed. These have been used in policy documents to indicate which areas are in need of intervention. In general, these models have not been subjected to validity assessment. This paper describes a validity assessment of 16 sets of synthetic estimates, by comparison of the models with national, regional and local survey-based estimates, and local mortality rate estimates. Model-based estimates of the prevalence of smoking, low fruit and vegetable consumption, obesity, hypertension and raised cholesterol are found to be valid.

Waist circumference, waist-hip ratio and BMI and their correlation with cardiovascular risk factors in Australian adults

Objectives. To compare body mass index (BMI), waist circumference and waist–hip ratio (WHR) as indices of obesity and assess the respective associations with type 2 diabetes, hypertension and dyslipidaemia.

Design and setting. A national sample of 11 247 Australians aged ≥25 years was examined in 2000 in a cross-sectional survey.

Main outcome measures. The examination included a fasting blood sample, standard 2-h 75-g oral glucose tolerance test, blood pressure measurements and questionnaires to assess treatment for dyslipidaemia and hypertension. BMI, waist circumference and WHR were measured to assess overweight and obesity.

Results. The prevalence of obesity amongst Australian adults defined by BMI, waist circumference and WHR was 20.8, 30.5 and 15.8% respectively. The unadjusted odds ratio for the fourth vs. first quartile of each obesity measurement showed that WHR had the strongest relationship with type 2 diabetes, dyslipidaemia (women only) and hypertension. Following adjustment for age, however, there was little difference between the three measures of obesity, with the possible exceptions of hypertension in women, where BMI had a stronger association, and dyslipidaemia in women and type 2 diabetes in men, where WHR was marginally superior.

Conclusions. Waist circumference, BMI and WHR identified different proportions of the population, as measured by both prevalence of obesity and cardiovascular disease (CVD) risk factors. Whilst WHR had the strongest correlations with CVD risk factors before adjustment for age, the three obesity measures performed similarly after adjustment for age. Given the difficulty of using age-adjusted associations in the clinical setting, these results suggest that given appropriate cut-off points, WHR is the most useful measure of obesity to use to identify individuals with CVD risk factors.

Risk factors for female sexual dysfunction in the general population : exploring factors associated with low sexual function and sexual distress

Introduction. No previous population-based studies have used validated instruments to measure female sexual dysfunction (FSD) in Australian women across a broad age range.
Aim. To estimate prevalence and explore factors associated with the  components of FSD.
Main Outcome Measures. Sexual Function Questionnaire measured low sexual function. Female Sexual Distress Scale measured sexual distress.
Methods. Multivariate analysis of postal survey data from a random sample of 356 women aged 20–70 years.
Results. Low desire was more likely to occur in women in relationships for 20–29 years (odds ratio 3.7, 95% confidence intervals 1.1–12.8) and less likely in women reporting greater satisfaction with their partner as a lover (0.3, 0.1–0.9) or who placed greater importance on sex (0.1, 0.03–0.3). Low genital arousal was more likely among women who were perimenopausal (4.4, 1.2–15.7), postmenopausal (5.3, 1.6–17.7), or depressed (2.5, 1.1–5.3), and was less likely in women taking hormone therapy (0.2, 0.04–0.7), more educated (0.5, 0.3–0.96), in their 30s (0.2, 0.1–0.7) or 40s (0.2, 0.1–0.7), or placed greater importance on sex (0.2, 0.05–0.5). Low orgasmic function was less likely in women who were in their 30s (0.3, 0.1–0.8) or who placed greater importance on sex (0.3, 0.1–0.7). Sexual distress was positively associated with depression (3.1, 1.2–7.8) and was inversely associated with better communication of sexual needs (0.2, 0.05–0.5). Results were adjusted for other covariates including age, psychological, socioeconomic, physiological, and relationship factors.
Conclusions. Relationship factors were more important to low desire than age or menopause, whereas physiological and psychological factors were more important to low genital arousal and low orgasmic function than relationship factors. Sexual distress was associated with both psychological and relationship factors.

Effects of dietary constituents on coronary heart disease risk factors

Coronary Heart Disease (CHD) is a major cause of death in Western countries. Mediterranean and Asian populations have a lower risk of death from CHD compared to Westernised population, as do vegetarian versus omnivorous populations. Dietary constituents of traditional diets consumed by these populations are thought to influence both the classical risk factors for CHD, and the more recently identified risk factors, such as oxidative modification of low density lipoprotein (LDL), LDL particle size, arterial compliance and haemostatic factors. The aim of this thesis was to examine the effects of several food components, particularly soybean and monounsaturated fat (MUFA), on CHD risk factors through 3 carefully controlled dietary interventions, and a cross-sectional study. A randomised crossover dietary intervention study was conducted in 42 healthy males to investigate the effect on CHD risk factors of replacing lean meat with tofu, a soybean product regularly consumed by Asian populations, while controlling all other dietary factors. The tofu diet resulted in significantly lower total cholesterol and triacylglycerol levels compared to the lean meat diet, and LDL particles that were more resistant to in vitro oxidative modification. However, insulin, fibrinogen, factor VII, and lipoprotein (a) were not significantly different on the 2 diets. A postprandial study was subsequently conducted to investigate any acute effects of a tofu test meal on the oxidative modification of LDL in 16 male subjects. There was no significant difference between the susceptibility of LDL to oxidative modification before and after the tofu meal. Twenty eight healthy subjects completed a separate randomised crossover dietary intervention comparing a high MUFA fat diet, using an Australian high oleic sunflower oil, with a low fat, high carbohydrate diet on CHD risk factors. The high MUFA oil diet significantly increased high density lipoprotein cholesterol compared to the low fat diet as well as producing LDL that were more resistant to oxidative modification. Neither the size of the LDL particle nor arterial compliance were significantly different on the 2 diets. Twelve matched pairs of vegetations and omnivores were also studies to compare the habitual diet of a low and higher risk population group, to compare their risk factors and identify dietary constituents that may explain the differences. The vegetarians consumed less saturated fat (SFA) and dietary cholesterol while consuming more polyunsaturated fat, dietary fibre and vitamin E compared to omnivores. The vegetarians had lower total cholesterol, LDL cholesterol and triacylglycerol levels compared to the omnivores and had LDL particles that were more resistant to in vitro oxidation. These findings contribute to our knowledge about the dietary constituents that can alter some CHD risk factors in healthy subjects, and which could reduce the risk of developing CHD. Investigations in high risk groups might reveal even more benefits.

Higher leptin levels in Asian Indians than Creoles and Europids : a potential explanation for increased metabolic risk

Background and purpose: Leptin predicts cardiovascular diseases and type 2 diabetes, diseases to which Asian Indians are highly susceptible. As a risk marker, leptin’s intra-individual and seasonal stability is unstudied and only small studies have compared leptin levels in Asian Indians with other populations. The aim of this study was to explore ethnicity related differences in leptin levels and its intra-individual and seasonal stability.

Methods: Leptin and anthropometric data from the northern Sweden MONICA (3513 Europids) and the Mauritius Non-communicable Disease (2480 Asian Indians and Creoles) studies were used. In both studies men and women, 25- to 74-year old, participated in both an initial population survey and a follow-up after 5–13 years. For the analysis of seasonal leptin variation, a subset of 1780 participants, 30- to 60-year old, in the Vasterbotten Intervention Project was used.

Results: Asian Indian men and women had higher levels of leptin, leptin per body mass index (BMI) unit (leptin/BMI) or per cm in waist circumference (WC; leptin/waist) than Creoles and Europids when adjusted for BMI (all P<0.0005) or WC (all P<0.005). In men, Creoles had higher leptin, leptin/BMI and leptin/waist than Europids when adjusted for BMI or WC (all P<0.0005). In women, Creoles had higher leptin/BMI and leptin/waist than Europids only when adjusted for WC (P<0.0005). Asian Indian ethnicity in both sexes, and Creole ethnicity in men, was independently associated with high leptin levels. The intra-class correlation for leptin was similar (0.6–0.7), independently of sex, ethnicity or follow-up time. No seasonal variation in leptin levels was seen.

Conclusion: Asian Indians have higher levels of leptin, leptin/BMI and leptin/waist than Creoles and Europids. Leptin has a high intra-individual stability and seasonal leptin variation does not appear to explain the ethnic differences observed here.

Chronic disease risk factors in rural Australia : results from the Greater Green Triangle risk factor surveys

The aim of this article was to assess the level and prevalence of major chronic disease risk factors among rural adults. Two cross-sectional surveys were carried out in 2004 and 2005 in the southeast of South Australia and the southwest of Victoria. Altogether 891 randomly selected persons aged 25 to 74 years participated in the studies. Surveys included a self-administered questionnaire, physical measurements, and a venous blood specimen for lipid analyses. Two thirds of participants had cholesterol levels ≥5.0 mmol/L. The prevalence of high diastolic blood pressure (≥90 mm Hg) was 22% for men and 10% for women in southeast of South Australia, and less than 10% for both sexes in southwest of Victoria. Two thirds of participants were overweight or obese (body mass index ≥25 kg/m2). About 15% of men and slightly less women were daily smokers. The abnormal risk factor levels underline the need for targeted prevention activities in the Greater Green Triangle region. Continuing surveillance of levels and patterns of risk factors is fundamentally important for planning and evaluating preventive activities.

Risk factors for chronic insomnia following hospitalisation

Aim. This paper reports a study whose purpose was to determine whether there is an increase in the incidence of chronic insomnia following hospitalization and, if so, to identify patients at risk.

Background. The consequences of difficulty sleeping in hospital have received scant attention from clinicians or researchers. Implicit in this lack of interest is the assumption that difficulty in sleeping is a transient reaction to hospitalization that will resolve on discharge, an assumption not empirically supported. It has been argued that in susceptible people this type of temporary disruption to sleep can be the catalyst for the development of chronic insomnia.

Method. Established sleep and depression rating instruments were used to monitor the sleep of 57 cardiac and 29 orthopaedic patients after elective surgery (n = 86), recruited through a hospital preadmission clinic.

Results. Preadmission chronic insomnia of 10% was consistent with general population prevalence estimates of 6–12%. Three months after discharge the incidence had almost doubled to 19%. Sixty-one per cent of this variance could be explained by hyperarousal, sleep hygiene issues, and dysfunctional cognitions about sleep. Depression was found to be a salient predictor but not an independent risk factor. Age, sex, and hospital-related data, such as score for difficulty sleeping in hospital, proved to be statistically insignificant.

Conclusions. The results support the role of hyperarousal and dysfunctional sleep attitudes and behaviours as stronger predictors of chronic insomnia than patient demographics or environmental issues. Given that most of the patients were ambivalent about how they slept in hospital, with high satisfaction (71%) in the presence of significant disruption (63%), preadmission sleep education given to these patients prior to admission potentially contributed to the development of more realistic expectations of the quality of in-hospital sleep.

Level of urbanization and noncommunicable disease risk factors in Tamil Nadu, India

Objective To investigate the poorly understood relationship between the process of urbanization and noncommunicable diseases (NCDs) through the application of a quantitative measure of urbanicity.

Methods We constructed a measure of the urban environment for seven areas using a seven-item scale based on data from the Census of India 2001 to develop an “urbanicity” scale. The scale was used in conjunction with data collected from 3705 participants in the World Health Organization’s 2003 STEPwise risk factor surveillance survey in Tamil Nadu, India, to analyse the relationship between the urban environment and major NCD risk factors. Linear and logistic regression models were constructed examining the relationship between urbanicity and chronic disease risk.

Findings
Among men, urbanicity was positively associated with smoking (odds ratio, OR: 3.54; 95% confidence interval, CI: 2.4–5.1), body mass index (OR: 7.32; 95% CI: 4.0–13.6), blood pressure (OR: 1.92; 95% CI: 1.4–2.7) and low physical activity (OR: 3.26; 95% CI: 2.5–4.3). Among women, urbanicity was positively associated with low physical activity (OR: 4.13; 95% CI: 3.0–5.7) and high body mass index (OR: 6.48; 95% CI: 4.6–9.2). In both sexes urbanicity was positively associated with the mean number of servings of fruit and vegetables consumed per day (P < 0.05).

Conclusion
Urbanicity is associated with the prevalence of several NCD risk factors in Tamil Nadu, India.

Adolescent and pre-conception risk factors for perinatal depression

Women who experienced psychiatric disorder during adolescence reported a 5̃-fold increased risk for depressive symptoms during pregnancy and during the postnatal period. A number of other adolescent and pre-conception risk factors, such as persistent stress and hormonal volatility, were also found to be implicated in the development of perinatal depression. Four case studies of children with profound and pervasive attachment-related disturbances are presented in the portfolio in order to highlight the shortcomings of the current diagnostic criteria for reactive attachment disorder in infancy or early childhood.