Life course influences on insulin resistance: findings from the British Women's Heart and Health Study

Clinical evaluation of patients living with obesity

Obesity is a significant public health concern which is implicated in cardiometabolic disease, mechanical complications and psychiatric sequelae. BMI is currently used for diagnosis; however, it has limited sensitivity for adiposity in certain circumstances. This has led to the development of risk stratification tools like the Edmonton Staging criteria and the Kings Obesity Staging Criteria: these facilitate and guide comprehensive obesity-related complication assessment. Healthcare professionals working within obesity clinics should adopt evidence-based communication strategies, including shared decision-making, motivational interviewing, and realistic goal setting. It is also vital to avoid weight-stigmatising terminology in all aspects of care, as this can negatively impact patients. Primary care plays an essential part in obesity care and should work to promptly identify cases, initiate treatment and forward on to specialist services where appropriate. Clinical evaluation of the patient living with obesity should take a holistic approach and involve input from bariatric physicians, dietitians, psychologists, and bariatric surgeons, wider members of the multi-disciplinary team should be involved where needed. Clinicians should take a detailed history, examination and order laboratory tests to investigate for complications. Overall, with appropriate evaluation, these assessments can guide patient management and facilitate long-term improvement in health.

Musculoskeletal Changes Across the Lifespan: Nutrition and the Life-Course Approach to Prevention

Aging is characterized by the progressive decline of muscle mass and function, the so-called sarcopenia. Also bone loss is widespread among older people. Sarcopenia and osteopenia/osteoporosis are associated with several adverse outcomes including falls, risk of fractures, functional decline, frailty, and mortality. Recently, the life-course approach to prevent or delay functional decline has become very popular. Regarding musculoskeletal health, there is suggestive evidence that acting during critical or sensitive periods of life in which each person build-up its biological reserves may influence the rate of functional decline in the later stages of life. A life-course approach to musculoskeletal health should take place during early life when plasticity allows more easily the attainment of the peak of the musculoskeletal system driven by environmental stimuli. The rate of the subsequent decline will depend on the peak previously reached. Nutrition and physical exercise are important environmental factors that can influence musculoskeletal development by favoring and maintaining peak bone and muscle mass and strength. Here we provide an overview of body composition changes occurring across the lifespan and strategies based on nutrition and physical exercise to support musculoskeletal health as well as minimizing losses during older life.

To tackle diabetes, science and health systems must take into account social context

An increasing amount of publications are recognizing that a person’s risk of diabetes and diabetes outcomes are influenced largely by social determinants of health. This renewed understanding of disease should influence health provision and diabetes research, but will it?

Birth Weight and Risk of Type 2 Diabetes Mellitus, Cardiovascular Disease, and Hypertension in Adults: A Meta-Analysis of 7 646 267 Participants From 135 Studies

Background Low birth weight has been associated with increased risk of type 2 diabetes mellitus, cardiovascular disease, and hypertension, but the risk at high birth weight levels remains uncertain. This systematic review and meta-analysis aimed to clarify the shape of associations between birth weight and aforementioned diseases in adults and assessed sex-specific risks. Methods and Results We systematically searched PubMed, EMBASE , and Web of Science for studies published between 1980 and October 2016. Studies of birth weight and type 2 diabetes mellitus (T2 DM ), cardiovascular disease ( CVD ), and hypertension were included. Random-effects models were used to derive the summary relative risks and corresponding 95% confidence intervals.We identified 49 studies with 4 053 367 participants assessing the association between birth weight and T2 DM , 33 studies with 5 949 477 participants for CVD , and 53 studies with 4 335 149 participants for hypertension and high blood pressure. Sex-specific binary analyses showed that only females had an increased risk of T2 DM and CVD at the upper tail of the birth weight distribution. While categorical analyses of 6 birth weight groups and dose-response analyses showed J-shaped associations of birth weight with T2 DM and CVD , the association was inverse with hypertension. The lowest risks for T2 DM , CVD , and hypertension were observed at 3.5 to 4.0, 4.0 to 4.5, and 4.0 to 4.5 kg, respectively. Conclusions These findings indicate that birth weight is associated with risk of T2 DM and CVD in a J-shaped manner and that this is more pronounced among females.

The association of parental and offspring educational attainment with systolic blood pressure, fasting blood glucose and waist circumference in Latino adults

Objective

The objective of the study is to evaluate the association of intergenerational educational attainment with cardiovascular disease (CVD) risk factors among US Latinos.

Methods

We used cross‐sectional data from the Niños Lifestyle and Diabetes Study, an offspring cohort of middle‐aged Mexican‐Americans whose parents participated in the Sacramento Latino Study on Aging. We collected educational attainment, demographic and health behaviours and measured systolic blood pressure (SBP), fasting glucose and waist circumference. We evaluated the association of parental, offspring and a combined parent–offspring education variable with each CVD risk factor using multivariable regression.

Results

Higher parental education was associated only with smaller offspring waist circumference. In contrast, higher offspring education was associated with lower SBP, fasting glucose and smaller waist circumference. Adjustment for parental health behaviours modestly attenuated these offspring associations, whereas adjustment for offspring health behaviours and income attenuated the associations of offspring education with offspring SBP and fasting glucose but not smaller waist circumference, even among offspring with low parental education.

Conclusions

Higher offspring education is associated with lower levels of CVD risk factors in adulthood, despite intergenerational exposure to low parental education.

Glucose intolerance develops prior to increased adiposity and accelerated cessation of estrous cyclicity in female growth-restricted rats

BACKGROUND

The incidence of metabolic disease increases in early menopause. Low birth weight influences the age at menopause. Thus, this study tested the hypothesis that intrauterine growth restriction programs early reproductive aging and impaired glucose homeostasis in female rats.

METHODS

Estrous cyclicity, body composition, and glucose homeostasis were determined in female control and growth-restricted rats at 6 and 12 mo of age; sex steroids at 12 mo.

RESULTS

Glucose intolerance was present at 6 mo of age prior to cessation of estrous cyclicity and increased adiposity in female growth-restricted rats. However, female growth-restricted rats exhibited persistent estrus and a significant increase in adiposity, fasting glucose, and testosterone at 12 mo of age (P < 0.05). Insulin release in response to a glucose challenge was blunted in conjunction with a reduction in protein expression of pancreatic glucose transporter type 2 and estrogen receptor-α at 12 mo of age in female growth-restricted rats (P < 0.05).

CONCLUSION

This study demonstrated that slow fetal growth programmed glucose intolerance that developed prior to early estrous acyclicity; yet, fasting glucose levels were elevated in conjunction with increased adiposity, accelerated cessation of estrous cyclicity and a shift toward testosterone excess at 12 mo of age in female growth-restricted rats.

Smaller kidney size at birth in South Asians: findings from the Born in Bradford birth cohort study

BACKGROUND

Rates of advanced chronic kidney disease and renal replacement therapy are higher in South Asian than in white British populations. Low birth weight is also more frequent in South Asian populations and has been associated with increased risks of kidney disease, perhaps due to a reduced nephron endowment.

METHODS

Using ultrasound scans at 34 weeks of gestation, we measured fetal kidney dimensions (transverse and anteroposterior diameters, length and circumference) and derived volume in a random sample of 872 white British and 715 South Asian participants in the Born in Bradford cohort study. Kidney measurements were compared between ethnic groups.

RESULTS

Birth weight for gestational age at 40 weeks was 200 g less in South Asian babies compared with white British babies. The mean kidney volume for gestational age was 16% lower in South Asian than in white British babies [8.79 versus 10.45 cm(3), difference 1.66 cm(3) (95% confidence interval 1.40-1.93, P < 0.001)]. The difference was robust after adjustment for maternal age, socio-economic factors, marital status, body mass index, smoking and alcohol use in pregnancy, parity, baby's gender and birth weight for gestational age [adjusted difference 1.38 cm(3) (0.97-1.84), P < 0.001]. There were smaller reductions in other fetal measures.

CONCLUSION

South Asian babies have smaller kidneys compared with white British babies, even after adjusting for potential confounders including birth weight. This finding may contribute to increased risks of adult kidney disease in South Asian populations.

Association of socioeconomic status with inflammatory markers: a two cohort comparison

OBJECTIVE

To assess the association between socioeconomic status (SES) and inflammatory markers using two different European population samples.

METHODS

We used data from the CoLaus (N=6412, Lausanne, Switzerland) and EPIPorto (N=1205, Porto, Portugal) studies. Education and occupational position were used as indicators of socioeconomic status (SES). High-sensitivity C-reactive protein (hs-CRP) was available for both cohorts. Interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were available in CoLaus; leukocyte count and fibrinogen in EPIPorto.

RESULTS

We showed that low SES was significantly associated with high inflammation in both studies. We also showed that behavioural factors contributed the most to SES differences in inflammation. In both studies the larger difference between the lowest and the highest SES was observed for hs-CRP. In the Swiss sample, a linear association between education and hs-CRP persisted after adjustment for all mediating factors and confounders considered (p for linear trend <0.001).

CONCLUSION

Large social differences exist in inflammatory activity, in part independently from demographic and behavioural factors, chronic conditions and medication use. SES differences in inflammation are also similar in countries with different underlying socioeconomic conditions.

Early life factors in relation to cardiovascular risk and cardiovascular disease in old age in Bergen: a Norwegian retrospective cohort study based on the Hordaland Health Study (HUSK)

Objectives

The fetal origins of adult disease hypothesis describes associations found for fetal or early-life exposures with cardiovascular risk and disease in adulthood. The extension or not of these associations into old age has received less attention. We investigated if maternal health and family circumstances were associated with cardiovascular risk factors and cardiovascular disease (CVD) in late life and discuss results in light of possible selection effects and measurement error.

Design

A retrospective cohort study based on community survey. We examined 224 possible associations between anthropometric measures, maternal health information and family socioeconomic status at birth versus CVD and CVD-related risk factors 72–74 years later.

Participants

Of 3341 participants in a community survey of people aged 72–74 years, we were able to trace birth records from a historical archive in a broadly representative subsample of 480.

Setting

Bergen, Norway

Main outcome measures

Established cardiovascular risk factors and indicators of CVD.

Results

Only 11 (4.9%) of these associations were found to be statistically significant, and no strong or consistent patterns in the associations between exposures and outcomes were found.

Conclusions

There was little evidence in this relatively elderly sample for an association between early life factors and CVD outcomes of clinical or public health relevance. Further research is required to confirm the extent to which a diminution of early life influences into old age, if genuine, can be accounted for by selective mortality, systematic bias or by dilution of effects due to competing risk factors.

Do mismatches between pre- and post-natal environments influence adult physiological functioning?

Purpose

Mismatches between pre- and post-natal environments have implications for disease in adulthood. However, less is known about how this mismatch can affect physiological systems more generally, especially at younger ages. We hypothesised that mismatches between pre- and post-natal environments, as measured by the measures of birthweight and adult leg length, would be associated with poorer biomarker levels across five key physiological systems in young adults.

Methods

Data were collected from 923, 36 year-old respondents from the West of Scotland Twenty-07 Study. The biomarkers were: systolic blood pressure (sBP); forced expiratory volume (FEV₁); glycated haemoglobin (HbA_1c); glomerular filtration rate (eGFR); and gamma-glutamyltransferase (GGT). These biomarkers were regressed against pre-natal conditions (birthweight), post-natal conditions (leg length) and the interaction between pre- and post-natal measures. Sex, childhood socioeconomic position and adult lifestyle characteristics were adjusted for as potential effect modifiers and confounders, respectively.

Results

There were no associations between birthweight and leg length and sBP, FEV₁, HbA_1c, or GGT. Higher birthweight and longer leg length were associated with better kidney function (eGFR). However, there was no evidence for mismatches between birthweight and leg length to be associated with worse sBP, FEV₁, HbA_1c, eGFR or GGT levels (P>0.05).

Conclusions

Our hypothesis that early signs of physiological damage would be present in young adults given mismatches in childhood environments, as measured by growth markers, was not proven. This lack of association could be because age 36 is too young to identify significant trends for future health, or the associations simply not being present.

Waist circumference is a better predictor than body mass index of insulin resistance in type 2 diabetes

Summay:

BACKGROUND

Insulin resistance is an important pathogenic factor in type 2 diabetes patents. An easy and efficiency measurement predicting insulin resistance; which can be done easily by type 2 patients is desired.

OBJECTIVE

To examine whether waist circumference is a better predictor of insulin resistance in type 2 diabetes than body mass index (BMI).

METHODS

From a population of 1356 registered diabetic patients, 144 who met (1) aged between 30 and 75 years, (2) being Chinese, (3) having had type 2 diabetes for more than one year, and (4) having been taking gliclazide and metformin for more than 6 months were enrolled in this study. The main outcome evaluated is the associations of HOMA insulin resistance index (HOMA index); which were assessed using multiple linear regression analysis.

RESULTS

The coefficients of multiple regression analysis with stepwise model showed that waist circumference (β = 0.35, p < 0.001) but not BMI (β = 0.01, p = 0.94), adiponectin (β = -0.25, p = 0.04) and hemoglobulin A1c% (HbA1c) (β = 0.25, p = 0.01) were the main predictors of HOMA index.

CONCLUSIONS

These initial findings indicate that waist circumference is a better predictor of insulin resistance in type 2 diabetes than BMI.

Short leg length, a marker of early childhood deprivation, is associated with metabolic disorders underlying type 2 diabetes: the PROMISE cohort study

OBJECTIVE

Short leg length, a marker of early childhood deprivation, has been used in studies of the association of early life conditions with adult chronic disease risk. The objective of this study was to determine the cross-sectional associations of leg length with measures of insulin sensitivity and β-cell function.

RESEARCH DESIGN AND METHODS

Subjects (n = 462) at risk for type 2 diabetes were recruited into the PROspective Metabolism and ISlet cell Evaluation (PROMISE) longitudinal cohort. Leg length was calculated from sitting and standing height at the 3-year clinical examination. Glucose tolerance status was determined using an oral glucose tolerance test. Insulin sensitivity was assessed using homeostasis model assessment of insulin resistance (HOMA-IR) and the Matsuda insulin sensitivity index (ISI), while the insulinogenic index over HOMA-IR (IGI/IR) and the insulin secretion sensitivity index 2 (ISSI-2) determined β-cell function. Multiple linear regression analysis was conducted, adjusting for covariates including age, sex, ethnicity, family history of diabetes, waist, and weight.

RESULTS

Leg length and leg-to-height ratio were significantly associated with HOMA-IR (β = -0.037, β = -10.49, respectively; P < 0.0001), ISI (β = 0.035, β = 8.83, respectively; P < 0.0001), IGI/IR (β = 0.021, P < 0.05; β = 7.60, P < 0.01, respectively), and ISSI-2 (β = 0.01, P < 0.03; β = 3.34, P < 0.01, respectively) after adjustment for covariates. The association of shorter leg length with lower insulin sensitivity was most evident for those with high waist circumferences.

CONCLUSIONS

Shorter legs were independently associated with lower insulin sensitivity and β-cell function, suggesting that early childhood deprivation may increase the risk of developing diabetes.

A complications-based clinical staging of obesity to guide treatment modality and intensity

PURPOSE OF REVIEW

The current medical model for obesity management is BMI-centric because BMI is the predominant measure used to gauge disease severity, as well as indications for various treatment modalities. Recent advancements in therapy and understanding of the relationship between BMI and obesity-related complications call for a re-examination of this approach.

RECENT FINDINGS

Advancements in treatment, including the recent approval of two new weight loss medications in the USA, have enabled development of new medical models for management of obesity. On the basis of accumulating data demonstrating the benefits of weight loss regarding multiple obesity-related complications (e.g., diabetes prevention, type 2 diabetes mellitus, cardiovascular disease risk, nonalcoholic steatohepatitis, sleep apnea), a complications-centric model is proposed that employs weight loss as a tool to treat and prevent obesity comorbidities. This model assures that the aggressiveness of therapy is commensurate with disease severity, and that therapy is directed at those obese patients who will benefit most from weight loss therapy. The treatment algorithm is comprehensive in addressing complications and quantitative when possible in the staging of risk or disease severity.

SUMMARY

A complications-centric approach to obesity management identifies patients who will benefit most from weight loss, and optimizes patient outcomes, benefit/risk ratio, and the cost-effectiveness of interventions.

Effects of birth size, post-natal growth and current size on insulin resistance in 9-year-old children: a prospective cohort study

The influence of pre-natal conditions on later type 2 diabetes risk factors such as insulin resistance (IR) may be mediated by post-natal growth trajectory. We aimed to investigate the association of body size at birth and 9 years with IR at 9 years. Using data from a prospective Australian cohort study, we examined the influence of body size from birth to 9 years [z-score for weight or body mass index (BMI)] on IR at 9 years (estimated by homeostasis model assessment). At age 9 years, 151 children provided a fasting blood sample. z-BMI at age 9 was positively associated with IR. Birth z-BMI was inversely associated with IR only after adjustment for z-BMI at age 9 years. This may be interpreted as an effect of accelerated growth between birth and 9 years on IR. There was a statistically significant interaction between birth and 9-year z-BMI. Results from regression models including z-BMI at all available time points (birth, 6 and 12 months, and 2, 3.5 and 9 years) indicate a possible inverse association between body size at 3.5 years and HOMA-IR at 9 years. Results were similar when the analyses were repeated with z-weight substituted for z-BMI. These results add to the body of evidence concerning the importance of growth in early life for later IR, and highlight a possible interaction between pre- and post-natal growth. The potential influence of growth at around 3.5 years for HOMA-IR at 9 years warrants further investigation.

UK-born Pakistani-origin infants are relatively more adipose than white British infants: findings from 8704 mother-offspring pairs in the Born-in-Bradford prospective birth cohort

Background

Previous studies have shown markedly lower birth weight among infants of South Asian origin compared with those of White European origin. Whether such differences mask greater adiposity in South Asian infants and whether they persist across generations in contemporary UK populations is unclear. Our aim was to compare birth weight, skinfold thickness and cord leptin between Pakistani and White British infants and to investigate the explanatory factors, including parental and grandparental birthplace.

Methods

We examined the differences in birth weight and skinfold thickness between 4649 Pakistani and 4055 White British infants born at term in the same UK maternity unit and compared cord leptin in a subgroup of 775 Pakistani and 612 White British infants.

Results

Pakistani infants were lighter (adjusted mean difference −234 g 95% CI −258 to −210) and were smaller in both subscapular and triceps skinfold measurements. The differences for subscapular and triceps skinfold thickness (mean z-score difference −0.27 95% CI −0.34 to −0.20 and −0.23 95% CI −0.30 to −0.16, respectively) were smaller than the difference in birth weight (mean z-score difference −0.52 95% CI −0.58 to −0.47) and attenuated to the null with adjustment for birth weight (0.03 95% CI −0.03 to 0.09 and −0.01 95% CI −0.08 to 0.05, respectively). Cord leptin concentration (indicator of fat mass) was similar in Pakistani and White British infants without adjustment for birth weight, but with adjustment became 30% higher (95% CI 17% to 44%) among Pakistani infants compared with White British infants. The magnitudes of difference did not differ by generation.

Conclusions

Despite being markedly lighter, Pakistani infants had similar skinfold thicknesses and greater total fat mass, as indicated by cord leptin, for a given birth weight than White British infants. Any efforts to reduce ethnic inequalities in birth weight need to consider differences in adiposity and the possibility that increasing birth weight in South Asian infants might inadvertently worsen health by increasing relative adiposity.

Risk of type 2 diabetes according to traditional and emerging anthropometric indices in Spain, a Mediterranean country with high prevalence of obesity: results from a large-scale prospective cohort study

BACKGROUND

Obesity is a major risk factor for type 2 diabetes mellitus (T2DM). A proper anthropometric characterisation of T2DM risk is essential for disease prevention and clinical risk assessement.

METHODS

Longitudinal study in 37 733 participants (63% women) of the Spanish EPIC (European Prospective Investigation into Cancer and Nutrition) cohort without prevalent diabetes. Detailed questionnaire information was collected at baseline and anthropometric data gathered following standard procedures. A total of 2513 verified incident T2DM cases occurred after 12.1 years of mean follow-up. Multivariable Cox regression was used to calculate hazard ratios of T2DM by levels of anthropometric variables.

RESULTS

Overall and central obesity were independently associated with T2DM risk. BMI showed the strongest association with T2DM in men whereas waist-related indices were stronger independent predictors in women. Waist-to-height ratio revealed the largest area under the ROC curve in men and women, with optimal cut-offs at 0.60 and 0.58, respectively. The most discriminative waist circumference (WC) cut-off values were 99.4 cm in men and 90.4 cm in women. Absolute risk of T2DM was higher in men than women for any combination of age, BMI and WC categories, and remained low in normal-waist women. The population risk of T2DM attributable to obesity was 17% in men and 31% in women.

CONCLUSIONS

Diabetes risk was associated with higher overall and central obesity indices even at normal BMI and WC values. The measurement of waist circumference in the clinical setting is strongly recommended for the evaluation of future T2DM risk in women.

Different impacts of metabolic syndrome components on insulin resistance in type 2 diabetes

Objective. To examine the different impacts of MS components on insulin resistance in type 2 diabetes. Methods. A number of subjects (144) who met the criteria of (1) age between 30 and 75 years, (2) had type 2 diabetes for more than one year, and (3) taking gliclazide and metformin for more than 6 months were enrolled. All subjects were assigned to one of the four HOMA index categories. The HOMA index quartile 4 denotes the highest insulin resistance. The main outcome evaluated is the odds ratios (ORs) of different MS components on HOMA index quartile 4. The characteristics in HOMA index quartiles and groups of nonmetabolic syndrome (NMS; number of components < 2), metabolic syndrome A (MSA; number of components = 2), and metabolic syndrome B (MSB; number of components > 2) were also evaluated. Results. The results showed that both MSA and MSB groups had higher ORs (5.9 and 13.8 times, resp.) than the NMS group; and that subjects with large waist circumference (LWC) and high triglyceride (HTG) level have higher ORs (6.1 and 2.6 times, resp.) in developing higher insulin resistance than normal control subjects. Conclusion. Type 2 diabetic patients with greater number of MS components have higher ORs in developing increased insulin resistance.

Association of lifecourse socioeconomic status with chronic inflammation and type 2 diabetes risk: the Whitehall II prospective cohort study

BACKGROUND

Socioeconomic adversity in early life has been hypothesized to "program" a vulnerable phenotype with exaggerated inflammatory responses, so increasing the risk of developing type 2 diabetes in adulthood. The aim of this study is to test this hypothesis by assessing the extent to which the association between lifecourse socioeconomic status and type 2 diabetes incidence is explained by chronic inflammation.

METHODS AND FINDINGS

We use data from the British Whitehall II study, a prospective occupational cohort of adults established in 1985. The inflammatory markers C-reactive protein and interleukin-6 were measured repeatedly and type 2 diabetes incidence (new cases) was monitored over an 18-year follow-up (from 1991-1993 until 2007-2009). Our analytical sample consisted of 6,387 non-diabetic participants (1,818 women), of whom 731 (207 women) developed type 2 diabetes over the follow-up. Cumulative exposure to low socioeconomic status from childhood to middle age was associated with an increased risk of developing type 2 diabetes in adulthood (hazard ratio [HR] = 1.96, 95% confidence interval: 1.48-2.58 for low cumulative lifecourse socioeconomic score and HR = 1.55, 95% confidence interval: 1.26-1.91 for low-low socioeconomic trajectory). 25% of the excess risk associated with cumulative socioeconomic adversity across the lifecourse and 32% of the excess risk associated with low-low socioeconomic trajectory was attributable to chronically elevated inflammation (95% confidence intervals 16%-58%).

CONCLUSIONS

In the present study, chronic inflammation explained a substantial part of the association between lifecourse socioeconomic disadvantage and type 2 diabetes. Further studies should be performed to confirm these findings in population-based samples, as the Whitehall II cohort is not representative of the general population, and to examine the extent to which social inequalities attributable to chronic inflammation are reversible.

Life course models of socioeconomic position and cardiovascular risk factors: 1946 birth cohort

PURPOSE

To identify the life course model that best describes the association between life course socioeconomic position (SEP) and cardiovascular (CVD) risk factors (ie, body mass index [BMI], systolic and diastolic blood pressure, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, and glycated hemoglobin) and explore BMI across the life course as mediators of the relationship.

METHODS

The Medical Research Council National Survey of Health and Development was used to compare partial F-tests of simpler nested life course SEP models corresponding to critical period, accumulation, and social mobility models with a saturated model. Then, the chosen life course model for each CVD risk factor was adjusted for BMI at age 53 and lifetime BMI (ages 4, 26, 43, and 53 years).

RESULTS

Among women, SEP was generally associated with CVD risk factors in a cumulative manner, whereas childhood critical period was the prominent model for men. When the best-fitting SEP models were used, we found that adjustment for BMI at age 53 reduced associations for all outcomes in both genders. Further adjustment for lifetime BMI (4, 26, 43, and 53 years) did not substantially alter most associations (except for triglycerides).

CONCLUSIONS

SEP at different points across life influences CVD risk factors differently in men and women.

Small birth size, adult overweight, and risk of acute myocardial infraction

BACKGROUND

The association between small size at birth and increased risk of cardiovascular disease in adulthood is well established. This relationship is commonly interpreted according to the "thrifty phenotype hypothesis," which states that the association is generated by a mismatch between fetal and postnatal nutrition. Empirical support for an interaction between impaired fetal growth and later overnutrition is, however, sparse and partly conflicting.

METHODS

The Stockholm Heart Epidemiology Program is a population-based case-control study of risk factors for acute myocardial infarction (MI); data were available for 1058 cases and 1478 controls. Using logistic regression, we studied the effect of size at birth, and its interactive effect with body mass index (BMI), at 3 occasions in adulthood, on the risk of MI. Biologic interaction was estimated with the synergy index.

RESULTS

Very low birth weight for gestational age was associated with increased risk of MI (odds ratio [OR] = 2.0; 95% confidence interval [CI] = 1.4-2.9; attributable fraction = 5%). In nonfatal cases, adjustment for waist-hip ratio, insulin resistance, blood pressure, and lipids reduced the point estimate somewhat. Low birth weight for gestational age in combination with high BMI at the time of the MI produced an OR of 10.8 (3.6-31.8) for MI compared with normal birth weight and normal BMI; the synergy index was 6.5 (95% CI = 1.8-24.0).

CONCLUSIONS

The synergism between small size at birth and high adult BMI supports the thrifty phenotype hypothesis. However, this mechanism seems to pertain to only a small fraction of the acute MI cases, implying minor public health importance.

Life-course socioeconomic position and type 2 diabetes mellitus: The Framingham Offspring Study

Evidence is lacking on whether the duration and timing of low socioeconomic position (SEP) across a person's life course may be associated with incidence of type 2 diabetes mellitus (T2D). The authors' objectives were to investigate associations between cumulative SEP and the incidence of T2D in the Framingham Offspring Study (n = 1,893; 52% women; mean baseline age = 34 years). Pooled logistic regression analyses demonstrated that age-adjusted cumulative SEP was associated with T2D in women (for low vs. high cumulative SEP, odds ratio (OR) = 1.92, 95% confidence interval (CI): 1.08, 3.42). Age-adjusted analyses for young-adulthood SEP (7.85 for ≤12 vs. >16 years of education, OR = 2.84, 95% CI: 1.03), active professional life SEP (for laborer vs. professional/executive/supervisory/technical occupations, OR = 2.40, 95% CI: 1.05, 5.47), and social-mobility frameworks (for declining life-course SEP, OR = 2.99, 95% CI: 1.39, 6.44; for stable low vs. stable high life-course SEP, OR = 1.85, 95% CI: 1.02, 3.35) all demonstrated associations between low SEP and T2D incidence in women. No association was observed between childhood SEP and T2D in women for father's education (some high school or less vs. any postsecondary education, OR = 1.26, 95% CI: 0.72, 2.22). In men, there was little evidence of associations between life-course SEP and T2D incidence. These findings suggest that cumulative SEP is inversely associated with incidence of T2D in women, and that this association may be primarily due to the women's educational levels and occupations.

Impact of early psychosocial factors (childhood socioeconomic factors and adversities) on future risk of type 2 diabetes, metabolic disturbances and obesity: a systematic review

Background

Psychological factors and socioeconomic status (SES) have a notable impact on health disparities, including type 2 diabetes risk. However, the link between childhood psychosocial factors, such as childhood adversities or parental SES, and metabolic disturbances is less well established. In addition, the lifetime perspective including adult socioeconomic factors remains of further interest.

We carried out a systematic review with the main question if there is evidence in population- or community-based studies that childhood adversities (like neglect, traumata and deprivation) have considerable impact on type 2 diabetes incidence and other metabolic disturbances. Also, parental SES was included in the search as risk factor for both, diabetes and adverse childhood experiences. Finally, we assumed that obesity might be a mediator for the association of childhood adversities with diabetes incidence. Therefore, we carried out a second review on obesity, applying a similar search strategy.

Methods

Two systematic reviews were carried out. Longitudinal, population- or community-based studies were included if they contained data on psychosocial factors in childhood and either diabetes incidence or obesity risk.

Results

We included ten studies comprising a total of 200,381 individuals. Eight out of ten studies indicated that low parental status was associated with type 2 diabetes incidence or the development of metabolic abnormalities. Adjustment for adult SES and obesity tended to attenuate the childhood SES-attributable risk but the association remained. For obesity, eleven studies were included with a total sample size of 70,420 participants. Four out of eleven studies observed an independent association of low childhood SES on the risk for overweight and obesity later in life.

Conclusions

Taken together, there is evidence that childhood SES is associated with type 2 diabetes and obesity in later life. The database on the role of psychological factors such as traumata and childhood adversities for the future risk of type 2 diabetes or obesity is too small to draw conclusions. Thus, more population-based longitudinal studies and international standards to assess psychosocial factors are needed to clarify the mechanisms leading to the observed health disparities.

Incidence of type 2 diabetes in two Indigenous Australian populations: a 6-year follow-up study

OBJECTIVE

To estimate the incidence of type 2 diabetes in two ethnically distinct Indigenous populations in north Queensland, Australia.

DESIGN, SETTING AND PARTICIPANTS

A community-based follow-up study of 1814 Australian Aboriginal and Torres Strait Islander adults from 1999 to 2007. Participants were initially free of diabetes and lived in 19 remote communities in Far North Queensland.

MAIN OUTCOME MEASURES

Fasting blood glucose level; diagnosis of diabetes; blood lipid levels; weight; waist circumference (WC); and blood pressure.

RESULTS

Of the 554 adults who completed the study, 100 developed diabetes over 3412 person-years (py) of follow-up. The incidence of diabetes was similar for Aboriginals (29.7 [95% CI, 20.4-38.4] per 1000 py) and Torres Strait Islanders (29.0 [95% CI, 21.8-38.6] per 1000 py) despite large differences in baseline body mass index (BMI) and WC. The age-standardised incidence for both populations was 30.5 per 1000 py. Obesity defined by WC increased the risk of developing diabetes for Aboriginals (rate ratio [RR], 2.0 [95% CI, 1.1-3.6]) and for Torres Strait Islanders (RR, 6.3 [95% CI, 2.5-16.1]) compared with normal WC. Presence of the metabolic syndrome (MetS) was a strong predictor of incident diabetes (adjusted hazard ratio, 2.4 [95% CI, 1.6-3.7]). For both groups, waist-to-hip ratio and the presence of the MetS better predicted diabetes than WC or BMI.

CONCLUSIONS

The incidence of diabetes in these Indigenous Australians is nearly four times higher than for the non-Indigenous population and 50% higher than the incidence reported 10 years ago in Australian Aboriginals. Currently used BMI cut-off points are not appropriate for Indigenous Australians to predict diabetes.

Health disparities beginning in childhood: a life-course perspective

In this article we argue for the utility of the life-course perspective as a tool for understanding and addressing health disparities across socioeconomic and racial or ethnic groups, particularly disparities that originate in childhood. Key concepts and terms used in life-course research are briefly defined; as resources, examples of existing literature and the outcomes covered are provided along with examples of longitudinal databases that have often been used for life-course research. The life-course perspective focuses on understanding how early-life experiences can shape health across an entire lifetime and potentially across generations; it systematically directs attention to the role of context, including social and physical context along with biological factors, over time. This approach is particularly relevant to understanding and addressing health disparities, because social and physical contextual factors underlie socioeconomic and racial/ethnic disparities in health. A major focus of life-course epidemiology has been to understand how early-life experiences (particularly experiences related to economic adversity and the social disadvantages that often accompany it) shape adult health, particularly adult chronic disease and its risk factors and consequences. The strong life-course influences on adult health could provide a powerful rationale for policies at all levels--federal, state, and local--to give more priority to investment in improving the living conditions of children as a strategy for improving health and reducing health disparities across the entire life course.

Lipid profiles in middle-aged men and women after famine exposure during gestation: the Dutch Hunger Winter Families Study

BACKGROUND

Many studies in humans have related birth weight to lipid profiles in adulthood. Fewer have estimated associations directly attributable to maternal nutrition during pregnancy.

OBJECTIVE

Our objective was to determine whether famine exposure during gestation is associated with a more atherogenic profile in adult offspring.

DESIGN

In 2003-2005, we studied 1) 359 singleton men and women born between January 1945 and March 1946 in clinics in Amsterdam, Rotterdam, and Leiden whose mothers were exposed to the famine during pregnancy; 2) 299 singletons born in the same 3 institutions during 1943 or 1947; and 3) 313 unexposed same-sex siblings of the above individuals. A lipid profile was obtained after an overnight fast.

RESULTS

Female offspring with prenatal famine exposure had a dyslipidemic pattern characterized by elevated total cholesterol (0.26 mmol/L; 95% CI: 0.07, 0.46; P = 0.007), triglycerides (0.17 mmol/L; 95% CI: 0.03, 0.31; P = 0.02), and LDL cholesterol (0.17 mmol/L; 95% CI: -0.01, 0.36; P = 0.06) compared with unexposed offspring. This pattern was not seen in men. The increases in total cholesterol and LDL cholesterol were independent of body mass index, waist circumference, and midthigh circumference. The increase in triglycerides was independent of midthigh circumference but was attenuated with control for either body mass index or waist circumference. There was no evidence for associations within specific gestational windows. No association was observed between prenatal famine exposure and HDL cholesterol in either sex.

CONCLUSION

In women, but not in men, aged approximately 58 y, we observed an association between prenatal undernutrition and elevated total cholesterol concentrations and triglycerides.

Alanine aminotransferase, gamma-glutamyltransferase, and incident diabetes: the British Women's Heart and Health Study and meta-analysis

OBJECTIVE

To estimate and compare associations of alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) with incident diabetes.

RESEARCH DESIGN AND METHODS

ALT and GGT were studied as determinants of diabetes in the British Women's Heart and Health Study, a cohort of 4,286 women 60-79 years old (median follow-up 7.3 years). A systematic review and a meta-analysis of 21 prospective, population-based studies of ultrasonography, which diagnosed nonalcoholic fatty liver disease (NAFLD), ALT, and GGT as determinants of diabetes, were conducted, and associations of ALT and GGT with diabetes were compared.

RESULTS

Ultrasonography-diagnosed NAFLD was associated with more than a doubling in the risk of incident diabetes (three studies). ALT and GGT both predicted diabetes. The fully adjusted hazard ratio (HR) for diabetes per increase in one unit of logged ALT was 1.83 (95% CI 1.57-2.14, I(2) = 8%) and for GGT was 1.92 (1.66-2.21, I(2) = 55%). To directly compare ALT and GGT as determinants of diabetes, the fully adjusted risk of diabetes in the top versus bottom fourth of the ALT and GGT distributions was estimated using data from studies that included results for both markers. For ALT, the HR was 2.02 (1.59-2.58, I(2) = 27%), and for GGT the HR was 2.94 (1.98-3.88, I(2) = 20%), suggesting that GGT may be a better predictor (P = 0.05).

CONCLUSIONS

Findings are consistent with the role of liver fat in diabetes pathogenesis. GGT may be a better diabetes predictor than ALT, but additional studies with directly determined liver fat content, ALT, and GGT are needed to confirm this finding.

A principal components approach to parent-to-newborn body composition associations in South India

BACKGROUND

Size at birth is influenced by environmental factors, like maternal nutrition and parity, and by genes. Birth weight is a composite measure, encompassing bone, fat and lean mass. These may have different determinants. The main purpose of this paper was to use anthropometry and principal components analysis (PCA) to describe maternal and newborn body composition, and associations between them, in an Indian population. We also compared maternal and paternal measurements (body mass index (BMI) and height) as predictors of newborn body composition.

METHODS

Weight, height, head and mid-arm circumferences, skinfold thicknesses and external pelvic diameters were measured at 30 +/- 2 weeks gestation in 571 pregnant women attending the antenatal clinic of the Holdsworth Memorial Hospital, Mysore, India. Paternal height and weight were also measured. At birth, detailed neonatal anthropometry was performed. Unrotated and varimax rotated PCA was applied to the maternal and neonatal measurements.

RESULTS

Rotated PCA reduced maternal measurements to 4 independent components (fat, pelvis, height and muscle) and neonatal measurements to 3 components (trunk+head, fat, and leg length). An SD increase in maternal fat was associated with a 0.16 SD increase (beta) in neonatal fat (p < 0.001, adjusted for gestation, maternal parity, newborn sex and socio-economic status). Maternal pelvis, height and (for male babies) muscle predicted neonatal trunk+head (beta = 0. 09 SD; p = 0.017, beta = 0.12 SD; p = 0.006 and beta = 0.27 SD; p < 0.001). In the mother-baby and father-baby comparison, maternal BMI predicted neonatal fat (beta = 0.20 SD; p < 0.001) and neonatal trunk+head (beta = 0.15 SD; p = 0.001). Both maternal (beta = 0.12 SD; p = 0.002) and paternal height (beta = 0.09 SD; p = 0.030) predicted neonatal trunk+head but the associations became weak and statistically non-significant in multivariate analysis. Only paternal height predicted neonatal leg length (beta = 0.15 SD; p = 0.003).

CONCLUSION

Principal components analysis is a useful method to describe neonatal body composition and its determinants. Newborn adiposity is related to maternal nutritional status and parity, while newborn length is genetically determined. Further research is needed to understand mechanisms linking maternal pelvic size to fetal growth and the determinants and implications of the components (trunk v leg length) of fetal skeletal growth.

Life-course socio-economic position, area deprivation and Type 2 diabetes: findings from the British Women's Heart and Health Study

OBJECTIVES

We examined whether area deprivation influenced risk of Type 2 diabetes, fasting blood glucose and insulin resistance over and above the effect of individual socio-economic position (SEP) measured across the life course.

METHODS

A cross-sectional analysis of 4286 women aged 60 to 79 years from 457 British electoral wards in 23 towns.

RESULTS

Area deprivation was positively associated with diagnosed [odds ratio (OR) 1.32, 95% confidence interval (CI) 1.13, 1.53, per quintile of area deprivation, n = 2895], but not undiagnosed Type 2 diabetes after adjustment for individual life-course SEP. This association was robust to adjustment for adult health behaviours and physiological risk factors. Insulin resistance [homeostasis model assessment (HOMA) score] increased by 1.90% (95% CI 0.01, 3.82, n = 2526) per quintile of area deprivation after adjustment for individual SEP, while fasting blood glucose increased by 0.69% (95% CI 0.16, 1.22, n = 2875) after adjustment for individual SEP.

CONCLUSIONS

Area level deprivation independently influences diagnosed Type 2 diabetes, insulin resistance and fasting blood glucose. Examination of more specific characteristics of places is needed to understand the mechanisms by which these effects arise.

Impaired glucose regulation and type 2 diabetes in children and adolescents

Diabetes mellitus in paediatric patients used to be almost exclusively type 1, but in recent years, case series as well as hospital-based and population-based studies indicated that the number of children and adolescents with type 2 diabetes (T2DM) has been increasing. This development is alarming since T2DM in youth is usually not an isolated condition, but accompanied by other cardiovascular risk factors such as obesity, dyslipidaemia, hypertension and low-grade inflammation. In adults, numerous studies provided detailed data on prevalence, incidence and risk factors for the development of T2DM, but for children and adolescents clinical and experimental data are still rather limited. This review provides an overview about the epidemiology and pathogenesis of T2DM in youth and about impaired glucose regulation as major risk factor for diabetes development with a special focus on the recent literature on clinical and lifestyle-related risk factors. Differences in incidence and prevalence across different populations indicate that ethnic background and genetic pre-disposition may be important risk determinants. In addition, epigenetic factors and foetal programming appear to confer additional risk before birth. Among the environmental and lifestyle-related risk factors there is evidence that obesity, hypercaloric diet, physical inactivity, socio-economic position (SEP), smoking, low-grade inflammation, psychosocial stress and sleeping patterns contribute to the risk for T2DM. However, the assessment of the relevance of risk factors and of incidence or prevalence estimates in youth is complicated by methodological issues that are also discussed.

Childhood socioeconomic position, gender, adult body mass index, and incidence of type 2 diabetes mellitus over 34 years in the Alameda County Study

OBJECTIVES

We examined the association between childhood socioeconomic position and incidence of type 2 diabetes and the effects of gender and adult body mass index (BMI).

METHODS

We studied 5913 participants in the Alameda County Study from 1965 to 1999 who were diabetes free at baseline (1965). Cox proportional hazards models estimated diabetes risk associated with childhood socioeconomic position and combined childhood socioeconomic position-adult BMI categories in pooled and gender-stratified samples. Demographic confounders and potential pathway components (physical inactivity, smoking, alcohol consumption, hypertension, depression, health care access) were included as covariates.

RESULTS

Low childhood socioeconomic position was associated with excess diabetes risk, especially among women. Race and body composition accounted for some of this excess risk. The association between childhood socioeconomic position and diabetes incidence differed by adult BMI category in the pooled and women-only groups. Adjustment for race and behaviors attenuated the risk attributable to low childhood socioeconomic position among the obese group only.

CONCLUSIONS

Childhood socioeconomic position was a robust predictor of incident diabetes, especially among women. A cumulative risk effect was observed for both childhood socioeconomic position and adult BMI, especially among women.

Offspring birth weight, gestational age and maternal characteristics in relation to glucose status at age 53 years: evidence from a national birth cohort

AIMS

We investigated pathways linking offspring birth weight to maternal diabetes risk in later life by taking into account a range of prospective early-life and adult maternal factors.

METHODS

In a national birth cohort study, we examined the relationship between offspring birth weight and maternal glycated haemoglobin (HbA1c) at age 53 years in 581 mothers who had a first birth between age 19 and 25 years, and had data on potential confounders or mediators.

RESULTS

Mean age at first birth was 21.5 years. After adjustment for maternal body mass index (BMI), mean percentage change in maternal HbA1c per kilogram increase in offspring birth weight was -1.8%[95% confidence interval (CI) -3.5, -0.1; P = 0.03]. This relationship was mostly accounted for by gestational age that was inversely related to maternal HbA1c (-0.9%; 95% CI -1.5, -0.4; P = 0.001). Other risk factors for high HbA1c were smoking and high BMI at 53 years. There was a significant interaction between offspring birth weight and maternal childhood social class (P = 0.01). Mothers from a manual background with higher birth weight offspring had lower HbA1c (BMI adjusted: -3.1%; 95% CI -5.0, -1.1); this was not observed for mothers from a non-manual background (BMI adjusted: 1.9%; 95% CI -1.3, 5.0).

CONCLUSIONS

Short gestational age and low offspring birth weight may be part of a pathway linking impaired early maternal growth to diabetes risk in later life. A second possible pathway linking higher offspring birth weight to later maternal glucose status was also identified. These potential pathways require further investigation in cohorts with a wider maternal age range so that the early targeting of public health initiatives can be assessed.

Associations of von Willebrand factor, fibrin D-dimer and tissue plasminogen activator with incident coronary heart disease: British Women's Heart and Health cohort study

BACKGROUND

Associations of three markers of thrombotic tendency, von Willebrand factor, tissue plasminogen activator antigen and fibrin D-dimer, with coronary heart disease have been reported in meta-analyses. It is not known, however, whether findings are generalizable to older women.

DESIGN

Prospective cohort of 3582 women aged 60-79 years randomly selected from 23 towns without evidence of cardiovascular disease at entry into the British Women's Heart and Health Study.

METHODS

Women were followed for 4.7 years for incident coronary heart disease. Cox proportional hazard models were used to compare the hazard ratio of coronary heart disease per doubling for each thrombotic factor.

RESULTS

In models adjusting for age and town only there was no association between von Willebrand factor or D-dimer and incidence of coronary heart disease, but there was a positive association of tissue plasminogen activator: coronary heart disease hazard ratio per doubling was 1.37 (95% confidence interval: 1.08-1.75). Adjustment for potential confounders (socio-economic position, smoking, lung function, physical activity, alcohol consumption, body mass index, waist-to-hip ratio) attenuated association to 1.20 (0.92-1.58). Further adjustment for risk factors that may be part of the same pathophysiological process linking tissue plasminogen activator to coronary heart disease (high density lipoprotein cholesterol, triglycerides, blood pressure, fasting glucose, insulin, C-reactive protein, fibrinogen) attenuated the hazard ratio to 1.05 (0.79-1.40).

CONCLUSION

In older women, tissue plasminogen activator was associated with incident coronary heart disease, but does not appear to be an independent risk factor for coronary heart disease as the association was attenuated by adjustment for confounding and other metabolic and vascular risk factors.

Behavioral Medicine Review: Promoting Healthy Lifestyles in Pediatric Populations

The upsurge in lifestyle-related, pediatric health problems has become the focus of widespread concern. This review discusses developmental considerations in lifestyle risk reduction and their implications for research, evidence-based practice, and public policy.

Relation of birth weight, body mass index, and change in size from birth to adulthood to insulin resistance in a female twin cohort

CONTEXT AND OBJECTIVES

Because an adverse intrauterine environment is thought to induce insulin resistance, our objective was to investigate the relationships between birth weight, BMI, and change in body size over the life course and insulin resistance. SETTING, DESIGN, AND PARTICIPANTS: We conducted a cross-sectional study in a cohort of 1194 female twins aged 18-74 yr. The relationship between birth weight and insulin resistance was analyzed using a regression method allowing for a simultaneous estimation of within- and between-pair influences. The approach allows the influence of individual fetal nutrition on adult insulin resistance to be distinguished from effects that are mediated by confounding factors in the maternal environment.

MAIN OUTCOME MEASURES

Insulin resistance was measured by the homeostasis model assessment.

RESULTS

Individual level regression analyses showed no significant relationship between birth weight and insulin resistance. There was a significant positive relationship between insulin resistance and current body mass index (BMI) (a 26% increase in insulin resistance per sd increase in BMI; confidence interval, 22.6-29.5%). This significant relationship was accounted for in equal parts by individual-specific effects and by confounding factors in the shared environment of the twins. The relationship with birth weight became significant only after adjustment for BMI and was mediated only through between-pair differences.

CONCLUSIONS

These results suggest that insulin resistance is influenced more by current body size than birth weight and that postnatal growth is potentially more important than fetal growth in the subsequent development of insulin resistance.

Behavioral Medicine Review: Promoting Healthy Lifestyles in Pediatric Populations

The upsurge in lifestyle-related, pediatric health problems has become the focus of widespread concern. This review discusses developmental considerations in lifestyle risk reduction and their implications for research, evidence-based practice, and public policy.

Gamma-Glutamyltransferase Is Associated With Incident Vascular Events Independently of Alcohol Intake

Objective— To investigate the association of γ-glutamyltransferase (GGT) with incident CHD and stroke. GGT is a marker of alcohol intake but may also reflect oxidative stress and nonalcoholic fatty liver disease. Alanine aminotransferase (ALT) is the enzyme most closely associated with liver fat content.

Methods and Results— Associations of GGT and ALT with incident CHD, stroke, and a combined outcome of CHD or stroke were examined in the British Women’s Heart and Health study (n=2961), and a meta-analysis of population based studies examining these associations was performed. In pooled analyses of fully adjusted results of 10 prospective studies, a change of 1 U/L of GGT was associated with a HR=1.20 (95% CI: 1.02, 1.40) for CHD; a HR=1.54 (95% CI: 1.20, 2.00) for stroke; and HR=1.34 (95% CI: 1.22, 1.48) for CHD or stroke. Heterogeneity was substantially decreased when 2 studies in Asian populations were excluded. In a subgroup of nondrinkers results were similar to the main analysis. Meta analyses of the only 2 studies that examined the association of ALT with incident cardiovascular events found a HR=1.18 (95% CI: 0.99, 1.41) for CHD and a HR=1.10 (95% CI: 0.89, 1.36) for CHD or stroke (combined).

Conclusion— GGT is associated with incident vascular events independently of alcohol intake. The mechanisms underlying this association remain unclear and require future study.

Prevalence of elevated alanine aminotransferase among US adolescents and associated factors: NHANES 1999-2004

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is a common cause of liver disease in children and adolescents. The majority of studies of NAFLD in children have been in select populations of the clinically obese. Study aims were to estimate the prevalence of elevated alanine aminotransferase (ALT, as a marker of NAFLD) in a general contemporary adolescent population and to identify leading risk factors for ALT elevation (>30 U/L).

METHODS

We analyzed data of adolescent participants (aged 12-19 years; N = 5586) in the National Health and Nutrition Examination Survey 1999-2004, a representative sample of the civilian noninstitutionalized US population.

RESULTS

The prevalence of elevated ALT levels (>30 U/L) was 7.4% among white adolescents, 11.5% among Mexican American adolescents, and 6.0% among black adolescents. Elevated ALT levels were prevalent in 12.4% of male subjects compared with 3.5% of female subjects. Multivariable associations with elevated ALT levels were found for sex (odds ratio [OR] male vs female, 7.7; 95% confidence interval [CI], 3.9-15.1), ethnicity (OR black vs white, 0.6; 95% CI, 0.3-1.3; OR Mexican American vs white, 1.6; 95% CI, 1.0-2.6), waist circumference (OR per 1 SD, 1.4; 95% CI, 1.0-2.0), and fasting insulin level (OR per 1 SD, 1.6; 95% CI, 1.2-2.1). Age, C-reactive protein levels, and triglyceride levels were also positively and socioeconomic position inversely associated with elevated ALT levels. The magnitude of associations were similar across ethnic groups.

CONCLUSIONS

ALT level is associated with waist circumference and insulin resistance even in a young population. These characteristics could be utilized to identify adolescents who may benefit from screening for NAFLD, offering an opportunity to prevent disease progression at an early age.

Obesity and diabetes in vulnerable populations: reflection on proximal and distal causes

Around the world obesity and diabetes are climbing to epidemic proportion, even in countries previously characterized by scarcity. Likewise, people from low-income and minority communities, as well as immigrants from the developing world, increasingly visit physicians in North America with obesity, metabolic syndrome, or diabetes. Explanations limited to lifestyle factors such as diet and exercise are inadequate to explain the universality of what can be called a syndemic, a complex and widespread phenomenon in population health produced by multiple reinforcing conditions. Underlying the problem are complex factors-genetic, physiological, psychological, familial, social, economic, and political-coalescing to overdetermine these conditions. These interacting factors include events occurring during fetal life, maternal physiology and life context, the thrifty genotype, the nutritional transition, health impact of urbanization and immigration, social attributions and cultural perceptions of increased weight, and changes in food costs and availability resulting from globalization. Better appreciation of the complexity of causation underlying the worldwide epidemic of obesity and diabetes can refocus the work of clinicians and researchers to work at multiple levels to address prevention and treatment for these conditions among vulnerable populations.

Life course pathways to adult-onset diabetes

Early life conditions, such as socioeconomic status (SES) and health, have the potential to set in motion multiple and reinforcing pathways that shape both the prevalence and onset of diabetes among older adults. Using data from the Health and Retirement Study (1998-2002) for persons age 51 years and older, we investigated the core mediating mechanisms linking early life conditions with diabetes prevalence in 1998 and onset over a 4-year follow-up period, focusing on adult achievement processes and obesity as key mechanisms. We found that father's education is negatively associated with diabetes prevalence for older men and women. However, no markers of early life SES are directly associated with older men's and women's onset of diabetes, and the negative effects of adult SES on diabetes onset pertain only to women. Early life health affects the onset of diabetes among women--but not the prevalence--and no evidence of this association was found for men. We found no evidence that obesity is an important mechanism connecting either early life or adult SES with diabetes development in men or women. We speculate that early life SES may accelerate the development of diabetes at younger ages, and that the pathways linking life course SES, early life health, and diabetes are partly gender-specific and biological in nature.

The association of life course socio-economic position with diagnosis, treatment, control and survival of women with diabetes: findings from the British Women's Heart and Health Study

OBJECTIVES

To examine the association of socio-economic position (SEP) with the diagnosis, treatment and control of diabetes, and with survival in women with and without Type 2 diabetes.

METHODS

Prospective cohort study of 4277 women from 23 centres in Great Britain, aged 60-79 years at baseline.

RESULTS

Of the 4277 women, 220 (5.1%) were known to have Type 2 diabetes and a similar number [n = 188 (4.4%)] had undiagnosed diabetes based on a single fasting glucose level > or = 7.0 mmol/l. Neither childhood nor adult SEP was associated with being correctly diagnosed amongst the 408 women with either diagnosed or undiagnosed diabetes. In both women with and without diabetes, SEP was associated with more adverse levels of fasting insulin, triglycerides, high-density lipoprotein cholesterol and body mass index, but was not associated with glycated haemoglobin in either group. Over the follow-up period, 395 women died. The hazard ratio for all-cause mortality per additional indicator of adverse SEP in adulthood in women with diabetes [1.40 (1.05, 1.85)] was similar to that in women without diabetes [1.26 (1.12, 1.41], P for difference in the two estimates = 0.70). Childhood SEP was not associated with survival.

CONCLUSION/INTERPRETATION

A considerable number of older women with Type 2 diabetes are not diagnosed, but SEP is not related to being correctly diagnosed. The marked socio-economic gradient for all-cause mortality is the same for women with and without diabetes and is not fully explained by conventional risk factors.

A comparison of associations of alanine aminotransferase and gamma-glutamyltransferase with fasting glucose, fasting insulin, and glycated hemoglobin in women with and without diabetes

Associations between biomarkers of nonalcoholic fatty liver disease (NAFLD) alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT), with 3 separate measures of glucose homeostasis: fasting glucose, fasting insulin and glycated hemoglobin (HbA1c) were studied and compared between women with and without diabetes in order to gain insight into the documented associations between NAFLD, insulin resistance and diabetes. Data from the British Women's Health and Heart Study, a random sample of British women aged 60-79 years (N = 3394; 3086 without diabetes and 308 with diabetes) was used. Associations of ALT and GGT with fasting glucose and HbA1c and of ALT with fasting insulin (and homeostasis model assessment of insulin resistance [HOMA]) are stronger in women with diabetes compared to women without diabetes (P for interaction < 0.001). GGT is associated with fasting insulin (and HOMA) to the same extent in all women, irrespective of diabetes status. Results excluding hyperinsulinemic women, i.e., in the highest fourth of the fasting insulin distribution, were similar to those obtained for all non-diabetic women as were results excluding women in the highest quartile of the alcohol consumption distribution and for women with ALT and GGT levels within the normal range. Associations did not differ substantially between obese and non-obese non-diabetic women.

CONCLUSION

elevation of liver enzymes and hepatic insulin resistance as reflected by fasting insulin occur in the early stages of insulin resistance and highlight the central role of the liver in insulin resistance in the general population.

Socio-economic position at three points in life in association with type 2 diabetes and impaired glucose tolerance in middle-aged Swedish men and women

BACKGROUND

It has been suggested that low socio-economic position (SEP) during childhood and adolescence predicts risk of adult type 2 diabetes. We investigated the associations between type 2 diabetes and childhood SEP (fathers' occupational position), participants' education and adult SEP (participants' occupational position). To determine possible independent associations between early SEP (fathers' occupational position and participants' education) and disease, we adjusted for adult SEP and factors present in adult life associated with type 2 diabetes.

METHODS

This cross-sectional study comprised 3128 men and 4821 women aged 35-56 years. All subjects have gone through a health examination and answered a questionnaire on lifestyle factors. At the health centre, an oral glucose tolerance test was administered and identified 55 men and 52 women with previously undiagnosed type 2 diabetes. Relative risks (RRs) with 95% CIs were calculated in multiple logistic regression analyses.

RESULTS

The age-adjusted RRs of type 2 diabetes if having a father with middle occupational position were 2.3 [Confidence interval (CI:1.0-5.1) for women and, 2.0 (CI:0.7-5.6) for men]. Moreover, low education was associated with type 2 diabetes in women, RR = 2.5 (CI:1.2-4.9). Low occupational position in adulthood was associated with type 2 diabetes in women, RR = 2.7 (CI:1.3-5.9) and men, RR = 2.9 (CI:1.5-5.7). The associations between early SEP and type 2 diabetes disappeared after adjustment for adult SEP and factors associated with type 2 diabetes.

CONCLUSION

The association between type 2 diabetes and low SEP during childhood and adolescence in middle-aged Swedish subjects disappeared after adjustment for adult SEP and adult risk factors of diabetes.

The mushroom Agaricus Blazei Murill in combination with metformin and gliclazide improves insulin resistance in type 2 diabetes: a randomized, double-blinded, and placebo-controlled clinical trial

BACKGROUND

Complementary and alternative medicine use in adults with type 2 diabetes is popular. Although most of the herbs and supplements appear to be safe, there is still insufficient evidence that demonstrates their definitive beneficial effects. This study was done to determine whether the supplement of Agaricus blazei Murill extract improves insulin resistance in type 2 diabetes.

MATERIALS AND METHODS

This study was a clinical randomized, double-blind, placebo-controlled trial. Of a population of 536 registered diabetes patients with 72 subjects (1) aged between 20 and 75 years, (2) being Chinese, (3) having type 2 diabetes for more than 1 year, and (4) having been taking gliclazide and metformin for more than 6 months were enrolled in this study. The enrolled patients were randomly assigned to either receiving supplement of Agaricus blazei Murill (ABM) extract or placebo (cellulose) 1500 mg daily for 12 weeks. Homeostasis model assessment for insulin resistance (HOMA-IR) was used as the major outcome measurement.

RESULTS

At the end of the study, subjects who received supplement of ABM extract (n = 29) showed significantly lower HOMA-IR index (3.6[standard deviation, 2.5] versus 6.6[standard deviation, 7.4], p = 0.04) than the control group (n = 31). The plasma adiponectin concentration increased 20.0(standard deviation, 40.7)% in the ABM group after 12 weeks of treatment, but decreased 12.0(20.0)% among those taking the placebo (p < 0.001).

CONCLUSIONS

Supplement of ABM extract improves insulin resistance among subjects with type 2 diabetes. The increase in adiponectin concentration after taking AMB extract for 12 weeks might be the mechanism that brings the beneficial effect. Studies with longer periods of follow-up should be conducted in the future.

Birth size, adult body composition and muscle strength in later life

OBJECTIVE

Low birth weight has been linked to lower lean body mass and abdominal obesity later in life, whereas high birth weight has been suggested to predict later obesity as indicated by high body mass index (BMI). We examined how birth weight was related to adult body size, body composition and grip strength.

DESIGN/SUBJECTS

Cross-sectional study on 928 men and 1075 women born in 1934-1944, with measurements at birth recorded.

MEASUREMENTS

Height, weight, waist and hip circumference and isometric grip strength were measured. Lean and fat body mass were estimated by bioelectrical impedance with an eight-polar tactile electrode system.

RESULTS

A 1 kg increase in birth weight corresponded in men to a 4.1 kg (95% CI: 3.1, 5.1) and in women to a 2.9 kg (2.1, 3.6) increase in adult lean mass. This association remained significant after adjustment for age, adult body size, physical activity, smoking status, social class and maternal size. Grip strength was positively related to birth weight through its association with lean mass. The positive association of birth weight with adult BMI was explained by its association with lean mass. Low birth weight was related to higher body fat percentage only after adjustment for adult BMI. Abdominal obesity was not predicted by low birth weight.

CONCLUSIONS

Low birth weight is associated with lower lean mass in adult life and thus contributes to the risk of relative sarcopenia and the related functional inability at the other end of the lifespan. At a given level of adult BMI, low birth weight predicts higher body fat percentage.

A life-course approach to measuring socioeconomic position in population health surveillance systems

Measuring socioeconomic position (SEP) in population chronic disease and risk factor surveillance systems is essential for monitoring socioeconomic inequalities in health over time. Life-course measures are an innovative way to supplement other SEP indicators in surveillance systems. A literature review examined the indicators of early-life SEP that could potentially be used in population health surveillance systems. The criteria of validity, relevance, reliability and deconstruction were used to determine the value of potential indicators. Early-life SEP indicators used in cross-sectional and longitudinal studies included education level, income, occupation, living conditions, family structure and residential mobility. Indicators of early-life SEP should be used in routine population health surveillance to monitor trends in the health and SEP of populations over time, and to analyse long-term effects of policies on the changing health of populations. However, these indicators need to be feasible to measure retrospectively, and relevant to the historical, geographical and sociocultural context in which the surveillance system is operating.

The relation between components of adult height and intimal-medial thickness in middle age: the Atherosclerosis Risk in Communities Study

The authors aimed to investigate the relation between components of adult height (leg and trunk length) and atherosclerosis in middle age, using data from 12,254 participants (aged 44-65 years) in the Atherosclerosis Risk in Communities (ARIC) Study. Intimal-medial thickness (IMT) as measured by B-mode ultrasound was the outcome, and exposures were trunk and leg lengths as estimated (using sitting height and the difference between sitting and standing height) at the first study examination in 1987-1989. The mean IMT was 0.73 (standard deviation, 0.17) mm. Greater leg length was associated with lower IMT, with the largest difference being for Black men (a 0.045 (95% confidence interval: 0.023, 0.068)-mm lower IMT per 10-cm higher leg length). Greater trunk length was associated with higher IMT, with the largest difference being for White men (a 0.024 (95% confidence interval: 0.005, 0.044)-mm higher IMT per 10-cm higher trunk length). Although the effect sizes were small, leg length was inversely associated with atherosclerosis, consistent with the results of other studies with cardiovascular disease outcomes.