Evidence of inappropriate cardiovascular risk assessment in middle-age women based on recommended cut-points for waist circumference.

BACKGROUND AND AIMS: Diverse waist circumference thresholds for assessment of metabolic and cardiovascular risk in Caucasians are recommended by different health professional organizations. We aimed to determine optimal sex-specific thresholds for anthropometric measures showing the strongest association with cardiovascular risk factors in a cohort of middle-aged Germans. METHODS AND RESULTS: Statistical analyses are based on data from 426 mothers and 267 fathers of participants of the Ulm Birth Cohort Study undergoing a clinical follow-up examination in 2008 (median age 41 years) using logistic regression analyses. The prevalence of many cardiometabolic risk factors was significantly higher in men than in women; hypertension: 45%/17% (p < 0.0001), apolipoprotein ratio B/A1 > 0.72: 35%/9% (<0.0001), hyperglycemia: 11%/14% (p = 0.3), which is in contrast to the predicted cardiovascular risk of 52%/70% and 24%/36% based on thresholds for waist circumference proposed by International Diabetes Federation and American Heart Association, respectively. We determined optimal thresholds for waist circumference between 90 and 95 cm for men and women. Using a threshold of 92 cm the prevalence of abdominal obesity was 59% in men and 24% in women, which was in agreement with the higher prevalence of overweight and obesity in men than in women (Body Mass Index (BMI) > 25: 64%/35%). The prediction of cardiometabolic risk factors by waist circumference and waist-to-height ratio did not outperform the prediction by BMI. In contrast to BMI, waist circumference was correlated with body height independent of sex. CONCLUSION: Currently proposed thresholds for waist circumference spuriously overestimate the cardiovascular risk in women, but not in men in a German population.

Association of pre- and post-natal parental smoking with offspring body mass index: an 8-year follow-up of a birth cohort.

BACKGROUND: Although many epidemiological studies have shown an association between maternal smoking during pregnancy and offspring overweight, it is still under debate whether intrauterine tobacco smoke exposure directly affects offspring obesity or if the association is rather due to confounding by lifestyle factors. OBJECTIVES: The association of parental smoking habits at pre- and post-natal periods with offspring body mass index (BMI) was investigated, whereas maternal smoking during pregnancy was validated by cord serum cotinine measurements. METHODS: Multivariable linear regression analysis, based on the German Ulm Birth Cohort Study of 1045 children born in 2000 with annual/biennial follow-up until the age of 8 years (n = 609), was conducted. RESULTS: BMI of offspring from mothers who smoked during pregnancy and non-smoking mothers differed significantly at 8 years. Maternal smoking during pregnancy was associated with an increase in BMI of 0.73 kg m(-2) [95% confidence interval: 0.21-1.25] in 8-year-old children after adjustment for multiple potential confounding variables. Both pre- and post-natal smoking of fathers (0.34 [0.01-0.66]/0.45 [0.08-0.81]) and of both parents (1.03 [0.43-1.63]/0.56 [0.14-0.98]) were likewise significantly associated with offspring BMI. CONCLUSIONS: The observed patterns suggest that residual confounding by living conditions in smoking families rather than specific intrauterine exposure to tobacco smoke may account for the increased risk of offspring overweight.

Reference values and early determinants of intra-abdominal fat mass in primary school children.

BACKGROUND: Intra-abdominal fat (IAF) is a valuable predictor of cardiovascular morbidity. However, neither reference values nor determinants are known in children. METHODS: IAF was assessed as sonographically measured intra-abdominal depth in 1,046 children [median age 7.6 years, interquartile range (IQR) 7.2-7.9; 54% boys] of the URMEL-ICE study. RESULTS: The intraclass correlation coefficient for intraobserver agreement was 0.93. The median IAF showed a significant gender difference (boys: 54.6 mm, IQR 50.1-59.3, vs. girls: 51.7 mm, IQR 46.3-56.4; p < 0.001). Age- and gender-specific centiles were generated. IAF showed a positive correlation to systolic blood pressure [regression coefficient (ß) = 0.24 mm Hg/mm; p < 0.001] and a negative correlation to HDL cholesterol (ß = -0.01 mmol/l/mm; p < 0.001). IAF showed a positive association with increased paternal and maternal BMI (ß = 0.28 mm/kg/m(2) and 0.27 mm/kg/m(2); p < 0.001), increased weight gain in the first 2 years of life (ß = 3.04 mm; p < 0.001), and maternal smoking during pregnancy (ß = 2.4 mm; p = 0.001). Increased parental education was negatively associated with IAF (maternal: ß = -0.65 mm/degree; p = 0.004, and paternal: ß = -0.61 mm/degree; p = 0.002). CONCLUSION: Sonography was a reliable tool to estimate IAF. Factors influencing IAF included rapid infant weight gain, smoking during pregnancy, and parental BMI and education. Since IAF showed an association with cardiovascular risk factors even in prepubertal children, it might become a valuable predictor of cardiovascular vulnerability.