Understanding nutrition

A practical and engaging introduction to the core principles of nutrition. A thorough introductory guide, this text will equip students with the knowledge and skills required to optimise health and well-being. With its focus on Australasia, the text incorporates current nutrition recommendations and public health nutrition issues relevant to those studying and working in nutrition in this region of the world. The text begins with core nutrition topics, such as diet planning, macronutrients, vitamins and minerals, and follows with chapters on diet and health, fitness, life span nutrition and food safety. With a consistent level and readability, careful explanations of all key topics (including energy metabolism and other complex processes), this is a book that connects with students; engaging them as it teaches them the basic concepts and applications of nutrition.

Age- and sex-related patterns of first fracture and fracture prevalence

There are few data documenting the pattern of prevalent fracture across the entire adult age range, so we aimed to address this gap by investigating the prevalence of fractures in an Australian cohort. All-cause (ever) fractures were identified for males and females enrolled in the Geelong Osteoporosis Study (Australia) using a combination of radiology-confirmed and self-reported data. First fractures were used to generate age-related frequencies of individuals who had ever sustained a fracture. Of 1,538 males and 1,731 females, 927 males and 856 females had sustained at least one fracture since birth. The proportion of all prevalent fractures in the 0-10 year age group was similar for both sexes (~10 %). In males, the proportion with prevalent fracture increased to 34.1 % for age 11-20 year. Smaller increases were observed into mid-life, reaching a plateau at ~50 % from mid to late life. The age-related prevalence of fracture for females showed a more gradual increase until mid-life. For adulthood prevalent fractures, approximately 20 % of males had sustained a first adulthood fracture in the 20-30 year age group, with a gradual increase up to the oldest age group (49.1 %), while females showed an exponential pattern of increase from the 20-30 year age group (6.8 %) to the oldest age group (60.4 %). In both sexes, those who had not sustained a fracture in childhood or early adulthood generally appeared to remain fracture-free until at least the sixth decade. When considering the prevalence of adulthood fractures across the age groups, males showed a gradual increase while females showed an exponential increase.

Western diet is associated with a smaller hippocampus: a longitudinal investigation

Background: Recent meta-analyses confirm a relationship between diet quality and both depression and cognitive health in adults. While the biological pathways that underpin these relationships are likely multitudinous, extensive evidence from animal studies points to the involvement of the hippocampus. The aim of this study was to examine the association between dietary patterns and hippocampal volume in humans, and to assess whether diet was associated with differential rates of hippocampal atrophy over time. Methods: Data were drawn from the Personality and Total Health Through Life Study and focused on a subsample of the cohort (n = 255) who were aged 60-64 years at baseline in 2001, completed a food frequency questionnaire, and underwent two magnetic resonance imaging scans approximately 4 years apart. Longitudinal generalized estimating equation linear regression models were used to assess the association between dietary factors and left and right hippocampal volumes over time. Results: Every one standard deviation increase in healthy "prudent" dietary pattern was associated with a 45.7 mm³ (standard error 22.9 mm³) larger left hippocampal volume, while higher consumption of an unhealthy "Western" dietary pattern was (independently) associated with a 52.6 mm³ (SE 26.6 mm³) smaller left hippocampal volume. These relationships were independent of covariates including age, gender, education, labour-force status, depressive symptoms and medication, physical activity, smoking, hypertension and diabetes. While hippocampal volume declined over time, there was no evidence that dietary patterns influenced this decline. No relationships were observed between dietary patterns and right hippocampal volume. Conclusions: Lower intakes of nutrient-dense foods and higher intakes of unhealthy foods are each independently associated with smaller left hippocampal volume. To our knowledge, this is the first human study to demonstrate associations between diet and hippocampal volume concordant with data previously observed in animal models.

Challenges of diabetes prevention in the real world : results and lessons from the Melbourne diabetes prevention study

OBJECTIVE: To assess effectiveness and implementability of the public health programme Life! Taking action on diabetes in Australian people at risk of developing type 2 diabetes.

RESEARCH DESIGN AND METHODS: Melbourne Diabetes Prevention Study (MDPS) was a unique study assessing effectiveness of Life! that used a randomized controlled trial design. Intervention participants with AUSDRISK score ≥15 received 1 individual and 5 structured 90 min group sessions. Controls received usual care. Outcome measures were obtained for all participants at baseline and 12 months and, additionally, for intervention participants at 3 months. Per protocol set (PPS) and intention to treat (ITT) analyses were performed.

RESULTS: PPS analyses were considered more informative from our study. In PPS analyses, intervention participants significantly improved in weight (-1.13 kg, p=0.016), waist circumference (-1.35 cm, p=0.044), systolic (-5.2 mm Hg, p=0.028) and diastolic blood pressure (-3.2 mm Hg, p=0.030) compared with controls. Based on observed weight change, estimated risk of developing diabetes reduced by 9.6% in the intervention and increased by 3.3% in control participants. Absolute 5-year cardiovascular disease (CVD) risk reduced significantly for intervention participants by 0.97 percentage points from 9.35% (10.4% relative risk reduction). In control participants, the risk increased by 0.11 percentage points (1.3% relative risk increase). The net effect for the change in CVD risk was -1.08 percentage points of absolute risk (p=0.013).

CONCLUSIONS: MDPS effectively reduced the risk of diabetes and CVD, but the intervention effect on weight and waist reduction was modest due to the challenges in recruiting high-risk individuals and the abbreviated intervention.

Cognitive remission: a novel objective for the treatment of major depression?

BACKGROUND: Cognitive dysfunction in major depressive disorder (MDD) encompasses several domains, including but not limited to executive function, verbal memory, and attention. Furthermore, cognitive dysfunction is a frequent residual manifestation in depression and may persist during the remitted phase. Cognitive deficits may also impede functional recovery, including workforce performance, in patients with MDD. The overarching aims of this opinion article are to critically evaluate the effects of available antidepressants as well as novel therapeutic targets on neurocognitive dysfunction in MDD.

DISCUSSION: Conventional antidepressant drugs mitigate cognitive dysfunction in some people with MDD. However, a significant proportion of MDD patients continue to experience significant cognitive impairment. Two multicenter randomized controlled trials (RCTs) reported that vortioxetine, a multimodal antidepressant, has significant precognitive effects in MDD unrelated to mood improvement. Lisdexamfetamine dimesylate was shown to alleviate executive dysfunction in an RCT of adults after full or partial remission of MDD. Preliminary evidence also indicates that erythropoietin may alleviate cognitive dysfunction in MDD. Several other novel agents may be repurposed as cognitive enhancers for MDD treatment, including minocycline, insulin, antidiabetic agents, angiotensin-converting enzyme inhibitors, S-adenosyl methionine, acetyl-L-carnitine, alpha lipoic acid, omega-3 fatty acids, melatonin, modafinil, galantamine, scopolamine, N-acetylcysteine, curcumin, statins, and coenzyme Q10. The management of cognitive dysfunction remains an unmet need in the treatment of MDD. However, it is hoped that the development of novel therapeutic targets will contribute to 'cognitive remission', which may aid functional recovery in MDD.

Risk of cardiovascular disease and diabetes in a working population with sedentary occupations

OBJECTIVE: To assess the prevalence of risk factors and risk for cardiovascular disease and Type 2 diabetes in employees with sedentary occupations enrolled in a workplace health-promotion program. METHODS: Participants (n = 762) were recruited from ten Melbourne workplaces, participating in a physical activity program. Demographic, behavioral, biomedical, and physical measurements were collected. RESULTS: The majority of employees were not meeting recommended guidelines for physical activity (62%), fruit intake (70%), vegetable intake (86%), body mass index (58%), or waist circumference (53%). Most had intermediate (53%) or high (7%) risk of developing Type 2 diabetes. CONCLUSIONS: The majority of Australian adults in sedentary occupations were not meeting guidelines for a number of chronic disease risk factors and a substantial proportion were unaware of their increased risk. This study supports the potential of chronic disease risk factor detection and intervention programs in the workplace.

Young maternal age at first birth and mental health later in life: does the association vary by birth cohort?

BACKGROUND: It is well established that maternal age at childbirth has implications for women's mental health in the short term, however there has been little research regarding longer term implications and whether this association has changed over time. We investigated longer term mental health consequences for young mothers in Australia and contrasted the effects between three birth cohorts. METHODS: Using thirteen waves of data from 4262 women aged 40 years or above participating in the Household, Income and Labour Dynamics in Australia Survey, we compared the mental health of women who had their first child aged 15-19 years, 20-24 years, and 25 years and older. Mental health was measured using the mental health component summary score of the SF-36. We used random-effects linear regression models to generate estimates of the association between age at first birth and mental health, adjusted for early life socioeconomic characteristics (country of birth, parents' employment status and occupation) and later life socioeconomic characteristics (education, employment, income, housing tenure, relationship status and social support). We examined whether the association changed over time, testing for effect modification across three successive birth cohorts. RESULTS: In models adjusted for early life and later life socioeconomic characteristics, there was strong evidence of an association between teenage births and poor mental health, with mental health scores on average 2.76 to 3.96 points lower for mothers aged younger than 20 years than for mothers aged 25 years and older (Late Baby Boom (born 1936-1945): -3.96, 95% CI -5.38, -2.54; Early Baby Boom (born 1946-1955): -3.01, 95% CI -4.32, -1.69; Lucky Few (born 1956-1965): -2.76, 95% CI -4.34, -1.18), and evidence of an association for mothers aged 20-24 years compared to mothers aged 25 years and older in the most recent birth cohort only (-1.09, 95% CI -2.01, -0.17). There was some indication (though weak) that the association increased in more recent cohorts. CONCLUSION: This study highlights that young mothers, and particularly teenage mothers, are a vulnerable group at high risk of poor mental health outcomes compared to mothers aged 25 years and above, and there was some suggestion (though weak) that the health disparities increased over time.

Health-related quality of life and metabolic control in children with type 1 diabetes : a prospective cohort study

OBJECTIVE—To assess change in health-related quality of life (HRQOL) in children with diabetes over 2 years and determine its relationship to change in metabolic control.

RESEARCH DESIGN AND METHODS—In 1998, parents of children aged 5–18 years attending a tertiary diabetes clinic reported their child’s HRQOL using the Child Health Questionnaire PF-50. Those aged 12–18 years also self-reported their HRQOL using the analogous Child Health Questionnaire CF-80. HbA_1c levels were recorded. In 2000, identical measures were collected for those who were aged ≤18 years and still attending the clinic.

RESULTS—Of 117 eligible subjects, 83 (71%) participated. Parents reported no significant difference in children’s HRQOL at baseline and follow-up. However, adolescents reported significant improvements on the Family Activities (P < 0.001), Bodily Pain (P = 0.04), and General Health Perceptions (P = 0.001) scales and worsening on the Behavior (P = 0.04) scale. HbA1c at baseline and follow-up were strongly correlated (r = 0.57). HbA_1c increased significantly (mean 7.8% in 1998 vs. 8.5% in 2000; P < 0.001), with lower baseline HbA_1c strongly predicting an increase in HbA_1c over the 2 years (r² = 0.25, P < 0.001). Lower parent-reported Physical Summary and adolescent-reported Physical Functioning scores at baseline also predicted increasing HbA_1c. Poorer parent-reported Psychosocial Summary scores were related to higher HbA_1c at both times but did not predict change in HbA_1c.

CONCLUSIONS—Changes in parent and adolescent reports of HRQOL differ. Better physical functioning may protect against deteriorating HbA_1c, at least in the medium term. While the HRQOL of children with diabetes does not appear to deteriorate over time, we should not be complacent, as it is consistently poorer than that of their healthy peers.

Health-related quality of life of overweight and obese children

Context: The negative effects of childhood overweight and obesity on quality of life (QOL) have been shown in clinical samples but not yet in population-based community samples.

Objective: To determine relationships between weight and health-related QOL reported by parent-proxy and child self-report in a population sample of elementary school children.

Design, Setting, and Participants: Cross-sectional data collected in 2000 within the Health of Young Victorians Study, a longitudinal cohort study commenced in 1997. Individuals were recruited via a random 2-stage sampling design from primary schools in Victoria, Australia. Of the 1943 children in the original cohort, 1569 (80.8%) were resurveyed 3 years later at a mean age of 10.4 years.

Main Outcome Measures: Health-related QOL using the PedsQL 4.0 survey completed by both parent-proxy and by child self-report. Summary scores for children'S total, physical, and psychosocial health and subscale scores for emotional, social, and school functioning were compared by weight category based on International Obesity Task Force cut points.

Results: Of 1456 participants, 1099 (75.5%) children were classified as not overweight; 294 (20.2%) overweight; and 63 (4.3%) obese. Parent-proxy and child self-reported PedsQL scores decreased with increasing child weight. The parent-proxy total PedsQL mean (SD) score for children who were not overweight was 83.1 (12.5); overweight, 80.0 (13.6); and obese, 75.0 (14.5); P < .001. The respective child self-reported total PedsQL mean (SD) scores were 80.5 (12.2), 79.3 (12.8), and 74.0 (14.2); P < .001. At the subscale level, child and parent-proxy reported scores were similar, showing decreases in physical and social functioning for obese children compared with children who were not overweight (all P < .001). Decreases in emotional and school functioning scores by weight category were not significant.

Conclusion: The effects of child overweight and obesity on health-related QOL in this community-based sample were significant but smaller than in a clinical sample using the same measure.

Parent-proxy and child self-reported health-related quality of life: using qualitative methods to explain the discordance

Background: Although parent-proxy reports of health-related quality of life (HRQOL) are only moderately correlated with child reported HRQOL, it remains unknown why these scores differ. The aim of this study was to use a qualitative methodology to examine why parents and children report different levels of HRQOL.

Method: The sample consisted of 15 parent–child pairs. A think-aloud technique was used where parents and children were given a generic HRQOL instrument (KIDSCREEN) and instructed to share their thoughts with the interviewer. Qualitative analyses were conducted to assess whether parents and children base their answer on different experiences or reasoning, have different response styles, or interpret the items differently.

Results: There was discordance between parents and children, in terms of rating scale and in terms of the reasoning for their answer. Children tended to have different response styles to parents, where for example, children tended to provide extreme scores (highest or lowest score) and base their response on one single example, more than parents. Parents and children interpreted the meaning of the items very similarly.

Discussion: This study provides evidence to suggest that discordance among parent-child pairs on KIDSCREEN scores may be as a result of different reasoning and different response styles, rather than interpretation of items. These findings have important implications when parent-proxy reported HRQOL is used to guide clinical/treatment decisions.