Dexter Canoy

Body Fat Distribution and Risk of Coronary Heart Disease in Men and Women in the European Prospective Investigation Into Cancer and Nutrition in Norfolk Cohort A Population-Based Prospective Study

Background— Body fat distribution has been cross-sectionally associated with atherosclerotic disease risk factors, but the prospective relation with coronary heart disease remains uncertain. Methods and Results— We examined the prospective relation between fat distribution indices and coronary heart disease among 24 508 men and women 45 to 79 years of age using proportional hazards regression. During a mean 9.1 years of follow-up, 1708 men and 892 women developed coronary heart disease. The risk for developing subsequent coronary heart disease increased continuously across the range of waist-hip ratio. Hazard ratios (95% CI) of the top versus bottom fifth of waist-hip ratio were 1.55 (1.28 to 1.73) in men and 1.91 (1.44 to 2.54) in women after adjustment for body mass index and other coronary heart disease risk factors. Hazard ratios increased with waist circumference, but risk estimates for waist circumference without hip circumference adjustment were lower by 10% to 18%. After adjustment for waist circumference, body mass index, and coronary heart disease risk factors, hazard ratios for 1-SD increase in hip circumference were 0.80 (95% CI, 0.74 to 0.87) in men and 0.80 (95% CI, 0.69 to 0.93) in women. Hazard ratios for body mass index were greatly attenuated when we adjusted for waist-hip ratio or waist circumference and other covariates. Conclusions— Indices of abdominal obesity were more consistently and strongly predictive of coronary heart disease than body mass index. These simple and inexpensive measurements could be used to assess obesity-related coronary heart disease risk in relatively healthy men and women.

Distribution of body fat and risk of coronary heart disease in men and women.

Purpose of review Earlier studies investigating the risk of developing coronary heart disease in relation to body fat distribution showed inconsistent results, and any sex-related difference in disease risk has not been adequately examined. This review aims to assess current findings on the prospective association between body fat distribution measures and coronary heart disease in men and women. Recent findings Current epidemiologic evidence suggests that waist circumference and waist–hip ratio, as indicators of abdominal adiposity, are positively related to coronary heart disease in men and women independently of body mass index and conventional coronary heart disease risk factors. But the magnitude and shape of the associations for these abdominal adiposity indices varied with adjustments for mediating and confounding factors. Interestingly, hip waist circumference was inversely associated with coronary heart disease after adjusting for waist circumference. Because waist and hips are positively correlated but have separate and opposite associations with coronary disease, using waist circumference alone may provide underestimated risk estimate if hip girth is not accounted for in the calculation of this risk. Summary For adipose tissue distribution assessment to be clinically useful, the ideal adiposity phenotype should provide a single risk estimate that captures the separate ‘effects’ of abdominal and peripheral adiposity. Although far from perfect, waist–hip ratio may capture separate effects of central and peripheral adiposity. This simple and inexpensive measure could be used to help improve coronary heart disease risk assessment.

Fat distribution, body mass index and blood pressure in 22,090 men and women in the Norfolk cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) study.

Objective To determine the relation between fat distribution and blood pressure, independent of body mass index. Design Cross-sectional, population-based study. Participants and methods Participants, 9936 men and 12 154 women aged 45–79 years, were recruited from general practices in Norfolk, United Kingdom for the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) study. Participants filled in a health and lifestyle questionnaire and their blood pressure and anthropometry were measured at a clinic. We mainly used waist–hip ratio (WHR) to assess body fat distribution. Results Systolic blood pressure (SBP) and diastolic blood pressure (DBP) increased linearly across the whole range of waist–hip ratio in both men and women. The relation was independent of age, body mass index (BMI) and other covariates. Separately, waist and hip circumferences were positively related to SBP and DBP. When adjusted for BMI, waist circumference was positively related to SBP (in women) and DBP (in both men and women), whereas hip circumference was inversely related to SBP (but not DBP) in both men and women. Stratifying by tertiles of waist and hip circumference, age- and BMI-adjusted SBP and DBP were highest among those with high waist and small hip circumference measures. Conclusion Waist–hip ratio was independently related to blood pressure. Waist–hip ratio could reflect the separate and opposite relations of waist and hip circumferences on blood pressure. Characterizing patterns of fat distribution may have implications in the assessment and control of obesity-related blood pressure elevation.

Early growth and adult respiratory function in men and women followed from the fetal period to adulthood.

Background: While some studies suggest that poor fetal growth rate, as indicated by lower birth weight, is associated with poor respiratory function in childhood, findings among adults remain inconsistent. A study was undertaken to determine the association between early growth and adult respiratory function. Methods: A longitudinal birth cohort study was performed of 5390 men and women born full term and prospectively followed from the fetal period to adulthood. Weight at birth and infancy were recorded, and forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were assessed by standard spirometry at age 31 years. Results: Adult FEV1 and FVC increased linearly with higher birth weight in both men and women with no apparent threshold. After adjustment for sex, adult height and other potential confounders operating through the life course, every 500 g higher birth weight was associated with a higher FEV1 of 53.1 ml (95% CI 38.4 to 67.7) and higher FVC of 52.5 ml (95% CI 35.5 to 69.4). These positive associations persisted across categories of smoking, physical activity and body mass index, with the lowest respiratory function noted among those with lower birth weight who were smokers, led a sedentary lifestyle or were overweight. Weight gain in infancy was also positively associated with adult lung function. Conclusion: Birth weight is continuously and independently associated with adult respiratory function. It is plausible that poor growth in early life may restrict normal lung growth and development, which could have long-term consequences on lung function later in life.

Cardiorespiratory fitness and body mass index of 9-11-year-old English children: A serial cross-sectional study from 1998 to 2004

Objective:To examine the changes over time in cardiorespiratory fitness and body mass index (BMI) of children.Design:Serial cross-sectional, population-based study.Setting:Primary schools in Liverpool, UK.Participants:A total of 15 621 children (50% boys), representing 74% of eligible 9–11-year olds in the annual school cohorts between 1998/9 and 2003/4, who took part in a 20m multi-stage shuttle run test (20mMST).Main outcome measures:Weight, height, BMI (kg/m2) and obesity using the International Obesity Taskforce definition.Results:Median (95% confidence interval) 20mMST score (number of runs) fell in boys from 48.9 (47.9–49.9) in 1998/9 to 38.1 (36.8–39.4) in 2003/4, and in girls from 35.8 (35.0–36.6) to 28.1 (27.2–29.1) over the same period. Fitness scores fell across all strata of BMI (P<0.001). Moreover, BMI increased over the same 6-year period even among children in fittest third of 20mMST.Conclusion:In a series of uniform cross-sectional assessments of school-aged children, BMI increased whereas cardiorespiratory fitness levels decreased within a 6-year period. Even among lean children, fitness scores decreased. Public health measures to reduce obesity, such as increasing physical activity, may help raise fitness levels among all children – not just the overweight or obese.

Size at birth, weight gain over the life course, and low-grade inflammation in young adulthood: northern Finland 1966 Birth Cohort study.

AIMS Low-grade inflammation might mediate associations between size at birth, early life growth, excessive weight gain, and subsequent risk of cardiovascular disease in adult life. Our aim was to investigate relationships between fetal growth, weight over the life course, and low-grade inflammation measured by serum high sensitivity C-reactive protein (CRP) levels at 31 years. METHODS AND RESULTS General population-based northern Finland 1966 Birth Cohort study of 5840 participants attending a clinical examination at 31 years, including measurement of CRP. Weight and height were assessed at birth, 12 months, and 14 and 31 years of age. CRP levels at 31 years were 16% [95% confidence interval (CI) 8, 23] higher per 1 kg lower birth weight, 21% (95% CI 2, 37) higher per 10 cm lower birth length, and 24% (95% CI 10, 36) higher per 1 kg/m3 lower ponderal index, after adjustment for potential confounders. Participants with highest tertile body mass index (BMI) at 31 years and lowest tertile birth weight had the highest average CRP levels. Per unit increase in BMI from 14 to 31 years was associated with 16% (95% CI 14, 17) higher CRP levels; the association was larger for those in the top BMI tertile at age 14 years. CONCLUSION Systemic low-grade inflammation may lie on the causal pathway that relates impaired fetal growth and weight gain from childhood to adulthood to adverse adult cardiovascular health. Lifestyle changes from early life might be an important step in reducing cardiovascular risk in adults.

Challenges in obesity epidemiology.

This paper was commissioned by the Foresight programme of the Office of Science and Innovation, Department of Trade and Industry

Birth Weight in Relation to Leisure Time Physical Activity in Adolescence and Adulthood: Meta-Analysis of Results from 13 Nordic Cohorts

Background Prenatal life exposures, potentially manifested as altered birth size, may influence the later risk of major chronic diseases through direct biologic effects on disease processes, but also by modifying adult behaviors such as physical activity that may influence later disease risk. Methods/Principal Findings We investigated the association between birth weight and leisure time physical activity (LTPA) in 43,482 adolescents and adults from 13 Nordic cohorts. Random effects meta-analyses were performed on categorical estimates from cohort-, age-, sex- and birth weight specific analyses. Birth weight showed a reverse U-shaped association with later LTPA; within the range of normal weight the association was negligible but weights below and above this range were associated with a lower probability of undertaking LTPA. Compared with the reference category (3.26–3.75 kg), the birth weight categories of 1.26–1.75, 1.76–2.25, 2.26–2.75, and 4.76–5.25 kg, had odds ratios of 0.67 (95% confidence interval: 0.47, 0.94), 0.72 (0.59, 0.88), 0.89 (0.79, 0.99), and 0.65 (0.50, 0.86), respectively. The shape and strength of the birth weight-LTPA association was virtually independent of sex, age, gestational age, educational level, concurrent body mass index, and smoking. Conclusions/Significance The association between birth weight and undertaking LTPA is very weak within the normal birth weight range, but both low and high birth weights are associated with a lower probability of undertaking LTPA, which hence may be a mediator between prenatal influences and later disease risk.

Age at Menarche and Risks of Coronary Heart and Other Vascular Diseases in a Large UK Cohort

Background— Early menarche has been associated with increased risk of coronary heart disease (CHD), but most studies were relatively small and could not assess risk across a wide range of menarcheal ages; few have examined associations with other vascular diseases. We examined CHD, cerebrovascular disease, and hypertensive disease risks by age at menarche in a large prospective study of UK women. Methods and Results— In 1.2 million women (mean±SD age, 56±5 years) without previous heart disease, stroke, or cancer, menarcheal age was reported to be 13 years by 25%, ⩽10 years by 4%, and ≥17 years by 1%. After 11.6 years of follow-up, 73 378 women had first hospitalization for or death from CHD, 25 426 from cerebrovascular disease, and 249 426 from hypertensive disease. Using Cox regression, we calculated relative risks for each vascular outcome by single year of menarcheal age. The relationship was U-shaped for CHD. Compared with women with menarche at 13 years, the adjusted relative risk for CHD for menarche at ⩽10 years of age was 1.27 (95% confidence interval, 1.22–1.31; P<0.0001) and for menarche at ≥17 years of age was 1.23 (95% confidence interval, 1.16–1.30; P<0.0001). U-shaped relationships were also seen for cerebrovascular and hypertensive disease, although the magnitudes of these risks for early and late menarche were smaller than those for CHD. Conclusions— In this cohort, the relation of age at menarche to vascular disease risk was U shaped, with both early and late menarche being associated with increased risk. Associations were weaker for cerebrovascular and hypertensive disease than for CHD.

Body mass index in young children and allergic disease: gender differences in a longitudinal study.

Background The increase in allergic diseases has occurred in parallel with the obesity epidemic, suggesting a possible association.