Changes in body fat distribution through menopause increase blood pressure independently of total body fat in middle-aged women: the Korean National Health and Nutrition Examination Survey 2007-2010

Abstract

Blood pressure in women increases sharply in middle age, especially after menopause. As the menopausal transition is known to induce changes in body fat distribution, the aim of this study was to investigate the effect of body fat distribution as compared with the effect of total body fat on blood pressure through the menopausal transition. We analyzed 1422 subjects aged 45-55 years using the database from the Korean National Health and Nutrition Examination Survey 2007-2010. The waist circumference (WC) of post-menopausal women was larger than that of pre-menopausal women (80.44 cm, 95% confidence interval (CI) 79.36-81.52 vs. 78.94 cm, 95% CI 78.27-79.61, P = 0.013), but there was no statistically significant difference in body mass index (BMI). Systolic and diastolic blood pressure (SBP and DBP) were significantly higher in post-menopausal women than in pre-menopausal women: SBP was 118.33 mm Hg, 95% CI 116.52-120.15 vs. 115.22 mm Hg, 95% CI 114.17-116.28 (P = 0.003) and DBP was 76.94 mm Hg, 95% CI 75.88-77.99 vs. 75.25 mm Hg, 95% CI 74.57-75.93 (P = 0.009). BMI and WC were positively correlated with BP. After adjustment for BMI, the correlation of WC with SBP remained significant (beta = 0.250, 95% CI 0.024-0.476, P = 0.030). In a stratified analysis, WC correlated with SBP in women with BMI < 25 kg m(-2) (beta = 0.358, 95% CI 0.138-0.579, P = 0.001), but not in women with BMI >= 25 kg m(-2). We conclude that the changes in body fat distribution through the menopausal transition are associated with SBP, independent of total body fat. This finding indicates that alterations in the localization of body fat are another cause of menopause-related changes in BP.