J.C. Seidell

Waist circumference action levels in the identification of cardiovascular risk factors: prevalence study in a random sample

Abstract Objective: To determine the frequency of cardiovascular risk factors in people categorised by previously defined “action g126 levels” of waist circumference. Design: Prevalence study in a random population sample. Setting: Netherlands. Subjects: 2183 men and 2698 women aged 20-59 years selected at random from the civil registry of Amsterdam and Maastricht. Main outcome measures: Waist circumference, waist to hip ratio, body mass index (weight (kg)/height (m2)), total plasma cholesterol concentration, high density lipoprotein cholesterol concentration, blood pressure, age, and lifestyle. Results: A waist circumference exceeding 94 cm in men and 80 cm in women correctly identified subjects with body mass index of >/=25 and waist to hip ratios >/=0.95 in men and >/=0.80 in women with a sensitivity and specificity of >/=96%. Men and women with at least one cardiovascular risk factor (total cholesterol >/=6.5 mmol/l, high density lipoprotein cholesterol </=0.9 mmol/l, systolic blood pressure >/=160 mm Hg, diastolic blood pressure >/=95 mm Hg) were identified with sensitivities of 57% and 67% and specificities of 72% and 62% respectively. Compared with those with waist measurements below action levels, age and lifestyle adjusted odds ratios for having at least one risk factor were 2.2 (95% confidence interval 1.8 to 2.8) in men with a waist measurement of 94-102 cm and 1.6 (1.3 to 2.1) in women with a waist measurement of 80-88 cm. In men and women with larger waist measurements these age and lifestyle adjusted odds ratios were 4.6 (3.5 to 6.0) and 2.6 (2.0 to 3.2) respectively. Conclusions: Larger waist circumference identifies people at increased cardiovascular risks.

Body mass index as a measure of body fatness: age- and sex-specific prediction formulas

In 1229 subjects, 521 males and 708 females, with a wide range in body mass index (BMI; 13.9-40.9 kg/m2), and an age range of 7-83 years, body composition was determined by densitometry and anthropometry. The relationship between densitometrically-determined body fat percentage (BF%) and BMI, taking age and sex (males = 1, females = 0) into account, was analysed. For children aged 15 years and younger, the relationship differed from that in adults, due to the height-related increase in BMI in children. In children the BF% could be predicted by the formula BF% = 1.51 x BMI-0.70 x age - 3.6 x sex + 1.4 (R2 0.38, SE of estimate (SEE) 4.4% BF%). In adults the prediction formula was: BF% = 1.20 x BMI + 0.23 x age - 10.8 x sex - 5.4 (R2 0.79, SEE = 4.1% BF%). Internal and external cross-validation of the prediction formulas showed that they gave valid estimates of body fat in males and females at all ages. In obese subjects however, the prediction formulas slightly overestimated the BF%. The prediction error is comparable to the prediction error obtained with other methods of estimating BF%, such as skinfold thickness measurements or bioelectrical impedance.

The prevention of overweight and obesity in children and adolescents : a review of interventions and programmes

Overweight and obesity are serious, large‐scale, global, public health concerns requiring population‐based childhood overweight and obesity prevention. The overall objective of this review is to identify aspects of successful childhood overweight prevention programmes. This objective will be met by assessing existing interventions quantitatively as well as qualitatively, identifying efficacy, effectiveness and implementation, and evaluating potential adverse effects of previous studies. This review was limited to school‐based studies with a quantitative evaluation using anthropometric outcomes and that intervene on diet or activity‐related behaviours. Quantitative and qualitative approaches are used to identify factors related to successful interventions as well as adverse consequences. Sixty‐eight per cent of the interventions, or 17 of the 25, were ‘effective’ based on a statistically significant reduction in body mass index (BMI) or skin‐folds for the intervention group. Four interventions were effective by BMI as well as skin‐fold measures. Of these, two targeted reductions in television viewing. The remaining two studies targeted direct physical activity intervention through the physical education programme combined with nutrition education. Of the interventions reported here, one was effective in reducing childhood overweight but was also associated with an increase in underweight prevalence. Few other studies reported outcomes for underweight. The majority of overweight/obesity prevention programmes included in this review were effective. Physical education in schools and reducing television viewing are two examples of interventions that have been successful. Because few studies report on underweight prevalence, this review recommends giving more attention to preventing adverse outcomes by reporting the intervention impact on the frequency distribution for both BMI and adiposity measures.

Fat and female fecundity: prospective study of effect of body fat distribution on conception rates

OBJECTIVES--To study the effect of body fat distribution in women of reproductive age on fecundity. DESIGN--Prospective cohort study of all women who had entered a donor insemination programme. SETTING--One fertility clinic serving a large part of the midwest of the Netherlands. SUBJECTS--Of 542 women attending the clinic for artificial insemination for the first time, 500 women were eligible for study. MAIN OUTCOME MEASURES--Probability of conception per cycle and number of insemination cycles before pregnancy or stopping treatment. RESULTS--A 0.1 unit increase in waist-hip ratio led to a 30% decrease in probability of conception per cycle (hazard ratio 0.706; 95% confidence interval 0.562 to 0.887) after adjustment for age, fatness, reasons for artificial insemination, cycle length and regularity, smoking, and parity. Increasing age was significantly related to lower fecundity (p < 0.05); very lean and obese women were less likely to conceive (p < 0.10) as were women with subfertile partners (p < 0.10). All other exposure variables were not significantly related to fecundity. CONCLUSIONS--Increasing waist-hip ratio is negatively associated with the probability of conception per cycle, before and after adjustment for confounding factors. Body fat distribution in women of reproductive age seems to have more impact on fertility than age or obesity.

Narrow hips and broad waist circumferences independently contribute to increased risk of non-insulin-dependent diabetes mellitus

Seidell JC, Han TS, Feskens EJM, Lean MEJ (National Institute of Public Health and the Environment, Bilthoven, the Netherlands, and Royal Infirmary, University of Glasgow, Glasgow, UK). Narrow hips and broad waist circumferences independently contribute to increased risk of non‐insulin‐dependent diabetes mellitus. J Intern Med 1997; 242: 401–406.

Predicting intra-abdominal fatness from anthropometric measures: the influence of stature

OBJECTIVE: To investigate the influence of height on the relationships between the intra-abdominal fat and anthropometric measures. SUBJECTS: Twenty healthy female volunteers aged 20–51 y from Aberdeen, and 71 men and 34 women aged 19–85 y from Nijmegen, The Netherlands. OUTCOME MEASURES: Intra-abdominal fat volumes by magnetic resonance imaging (MRI) in Aberdeen and cross-sectional areas at L4-L5 level by computerised tomography (CT) in Nijmegen, height, body mass index (BMI), waist circumference, waist sagittal and transverse diameters, waist to hip ratio, and skinfolds. RESULTS: In the MRI study the women with BMI 20–33 kg/m2, waist circumference 62–97 cm, height 148–172 cm, and intra-abdominal fat volume 0.07–2.66 kg, waist circumference gave the highest correlation of simple indices with intra-abdominal fat volume, explaining 77.8% of variance. Single cross-sectional MRI cuts predicted volume with r=0.94–0.99. Height in various levels of index power was not related to waist circumference, waist diameters, BMI, or skinfolds and did not improve prediction of intra-abdominal fat volume or of cross-sectional intra-abdominal fat area at any level. The CT study of men and women with BMI 18–32 kg/m2 and 19–38 kg/m2, waist circumference 71–112 cm and 74–125 cm, height 158–197 cm and 151–182 cm, and intra-abdominal fat area 13–274 cm2 and 19–221 cm2 respectively, height also had little influence on the relationships of intra-abdominal fat area with waist circumference or with any other indices of adiposity in linear or quadratic models. Compared to younger subjects, intra-abdominal fat area was higher in older subjects for a given waist circumference. CONCLUSIONS: Height does not importantly influence the differences in measures of adiposity or intra-abdominal fat volume in women, or intra-abdominal fat area in both sexes. Age does influence the prediction of intra-abdominal fat from waist circumference, but waist circumference alone has a predictable simple relationship with intra-abdominal fat volume or area, which is likely to relate to the prediction of health risk for health promotion.

Long-term and recent time trends in the prevalence of obesity among Dutch men and women.

OBJECTIVE: To describe long-term and recent time trends in the prevalence of obesity by age and educational level.DESIGN: Repeated cross-sectional population based monitoring studies.SETTING: Consultation Bureau Heart Project 1976–1980, Monitoring Project on Cardiovascular Diseases 1987–1991 and Monitoring project on risk factors for chronic diseases (MORGEN-) project 1993–1997.SUBJECTS: A total of 29 141 men and women aged 37–43 y (1976–1997); and 21 926 men and women aged 20–59 y (1993–1997).MEASUREMENTS: Body mass index, ie weight divided by height squared.RESULTS: Between 1976 and 1997 the prevalence of obesity increased from 4.9 to 8.5% among men and from 6.2 to 9.3% among women aged 37–43 y. Between 1993 and 1997, the prevalence of obesity among men aged 20–59 y was 8.5% and increased by 0.54 percentage points per year (P<0.01). The prevalence of obesity among women was 9.6% and increased by 0.35 percentage points per year (P=0.07). The increase in the prevalence of obesity in the period 1993–1997 was strongest in men with a relatively low educational level and in women with a high educational level.CONCLUSIONS: There has been a steady increase in the prevalence of obesity in the last quarter of the 20th century. Also, a recent increase in the prevalence of obesity has been seen. To stop the increase in the prevalence of obesity, effective strategies for the management and prevention of obesity need to be developed.

The prevalence of low back pain and associations with body fatness, fat distribution and height.

OBJECTIVES: To examine the associations of low back pain symptoms with waist circumference, height, waist to hip ratio and body mass index, and to test the interactions between (1) waist circumference and height, and (2) waist to hip ratio and body mass index. SETTING: Cross-sectional study set in The Netherlands of a random sample of 5887 men and 7018 women aged 20–60 y. RESULTS: The prevalences of low back pain in men and women in the past 12 months were 46% and 52%, of whom 17% and 21% had low back pain for a total of 12 or more weeks, and 13% and 18% had symptoms suggestive of intervertebral disc herniation. After adjustments for age, smoking and education, more women in the highest tertile of waist circumference reported low back pain in the past 12 months (odds ratio=1.2, 95% confidence interval: 1.1–1.4), low back pain for a total of 12 or more weeks (odds ratio=1.5, 95% confidence interval: 1.3–1.8), and intervertebral disc herniation symptoms (odds ratio=1.3, 95% confidence interval: 1.1–1.6) than women in the lowest waist tertile. Corresponding values of low back pain symptoms for women with high body mass index or high waist to hip ratio were similar to those with high waist. There were no significant differences between men in different tertiles of waist, waist to hip ratio or body mass index reporting low back pain symptoms. Tallest subjects did not report low back pain symptoms more often than shortest subjects. There were no significant interactions between waist and height or between waist to hip ratio and body mass index on low back pain symptoms. CONCLUSIONS: Women who are overweight or with a large waist have a significantly increased likelihood of low back pain. There are no significant interactions between waist and height, or waist to hip ratio and body mass index on low back pain symptoms.

Abdominal diameters as indicators of visceral fat: comparison between magnetic resonance imaging and anthropometry

The aim of the present study was to investigate the usefulness of abdominal diameters to indicate visceral fat, their relationship with serum lipids and their capability of detecting changes in visceral fat. Before and after weight loss, visceral and subcutaneous fat, and the sagittal and transverse diameters were assessed by magnetic resonance imaging (MRI) in forty-seven obese men and forty-seven premenopausal obese women with an initial body mass index of 31.0 (SD 2.4) kg/m2. In a subsample (n 21), diameters, were also measured by anthropometry in the standing and supine positions. They were strongly correlated with the diameters derived from the MRI scans. Serum levels of total and HDL-cholesterol and triacylglycerol were measured before weight loss. In women the sagittal diameter correlated less strongly with visceral fat than anthropometrically-assessed waist circumference and waist:hip ratio (WHR). In men these associations were comparable. Changes in visceral fat with weight loss were more strongly correlated with changes in the sagittal diameter and sagittal:transverse diameter ratio (STR) than with changes in waist circumference or WHR in men. In women, changes in the anthropometric variables and the separate diameters (except STR) were not associated with visceral fat loss. In men, but not in women, both the sagittal diameter and the visceral fat area were related to serum lipids. It is concluded that the sagittal diameter and STR may have advantages over waist circumference and WHR in men, particularly in assessing changes in visceral fat, but this could not be demonstrated in women. The ability to predict visceral fat from circumferences and diameters or their ratios is, however, limited in obese men and women.

Physical activity and dietary fiber determine population body fat levels: the Seven Countries Study

BACKGROUND: A global epidemic of obesity is developing. Current prevalence rates are about 20–25% in American adults and 15–20% in Europeans.OBJECTIVE: We investigated the association between population levels of physical activity, dietary fat, dietary fiber and indicators of body fat.DESIGN: Cross-cultural study of 16 cohorts of, in total, 12 763 middle-aged men in seven countries. These men were examined between 1958 and 1964.MEASUREMENTS: Height, weight and subscapular skinfold thickness were measured. Information about job-related physical activity and diet was gathered by questionnaire.RESULTS: The population average body mass index (weight/height2) varied between 21.8 and 26.0 kg/m2 and the population average subscapular skinfold thickness between 8.4 and 23.7 mm. The population average physical activity index and dietary fiber intake were both strongly inversely related to population average subscapular skinfold thickness and explained together 90% of the variance in subscapular skinfold thickness. Similar but less strong results were obtained for average population body mass index.CONCLUSION: At the population level job-related physical activity and dietary fiber but not dietary fat, are important determinants of subscapular skinfold thickness.