Sex Differences in the Effects of Weight Reduction on Future Blood Pressure Elevation in a Mildly Obese Middle-Aged Population

Abstract

mildly overweight. Focusing on this point, the Japan Society for the Study of Obesity defines a BMI ≥25 kg/m 2 as obese for the Japanese population. Many studies have reported on the importance of WL in preventing BP elevation. However, sex differences in the effects of WL on increases in BP have not been adequately elucidated. In the Japanese population, the prevalence of hypertension increases with age in both men and women. 11 The proportion of obesity by age differs between men and women. In men, the prevalence of obesity peaks for those aged in their 40 s and then gradually decreases. In women, the prevalence of obesity increases consistently until the seventh decade. 12 Because there are sex differences in trends in the prevalence of obesity and hypertension by age, the effects of WL on future BP increases may vary between men and women. To prevent unfavorable outcomes due to hypertension in old age, it is necessary to examine the effects of WL on H ypertension is a well-known risk factor for cardio-vascular disease morbidity and mortality; thus, the development of hypertension needs to be prevented to avoid cardiovascular diseases. 1,2 The association between obesity and hypertension has been extensively researched and confirmed. Weight gain increases blood pressure (BP); 3,4 conversely, weight loss (WL) reduces the BP or suppresses its elevation. 5,6 Therefore, WL through exercise and lifestyle improvement is recommended as one of the first-line therapies for hypertension. 7,8 The World Health Organization defines obesity as a body mass index (BMI) ≥30.0 kg/m 2. In Japan, the proportion of individuals with a BMI ≥30 kg/m 2 is 2.2% for men and 3.5% for women, 9 which is lower than in Western countries. However, individuals with a BMI of 26-28 kg/m 2 are reported to have high odds ratios for developing hypergly-cemia, hypertension, and dyslipidemia. 10 Japanese people are likely to develop health problems even though they are Background: The effectiveness of weight loss (WL) in preventing blood pressure (BP) elevation is common knowledge; however, the effect of sex differences is not known.