Different mechanisms in weight loss-induced blood pressure reduction between a calorie-restricted diet and exercise

Abstract

The present study compared the effectiveness of a mild calorie-restricted diet (D) alone, exercise (EX) alone and a combination of D+EX on weight loss-induced blood pressure (BP) reduction over 24 weeks. We focussed especially on the relationship between sympathetic nervous activity, as indicated from measures of plasma norepinephrine (NE), and insulin resistance (homeostasis model of insulin resistance, HOMA-IR). The three groups each comprised 30 obese, hypertensive men. Body mass index (BMI), fat mass, waist-to-hip ratio, BP, plasma NE and HOMA-IR were measured every 2 weeks during the first 4 weeks and subsequently every 4 weeks for the next 20 weeks. All basal parameters were similar among the three groups. At 24 weeks, the combination group with D+EX comprised a significantly higher prevalence of normotensive subjects than the D alone or EX alone group (Po0.05). In the D alone group, plasma NE was decreased significantly at 2 weeks, reductions in BMI, fat mass and BP were observed at 8 weeks, and waist-to-hip ratios and HOMA-IR were decreased at 12 weeks. In comparison, in the EX alone group, significant reductions of fat mass and HOMA-IR were observed at 4 weeks. Plasma NE and HOMA-IR were reduced at 8 weeks while decreases in BP were detected at 12 weeks. In the D+EX group, significant reductions in plasma NE were observed at 2 weeks followed by significant decreases in BMI, fat mass, waist-to-hip ratio, BP levels and HOMA-IR at 4 weeks. The magnitudes of reductions of all parameters were greatest in the D+EX group. These results demonstrate that D+EX exerts a stronger ameliorative effect on weight loss, weight loss-induced BP reduction, normalization of BP, sympathetic activation and insulin resistance compared with D or EX alone. D and EX might, perhaps, exert different mechanisms on weight loss and weight loss-induced BP reduction; however, a combination of caloric restriction and exercise is preferred to control BP levels in obese hypertensive patients.

Cardiovascular and Renal Complications in Obesity and Obesity-Related Medical Conditions: Role of Sympathetic Nervous Activity and Insulin Resistance

“…Obesity, hypertension and type 2 diabetes are characterized as stimulated sympathetic nervous activity and insulin resistance states, indicating renal injury and ESRD are strongly related to sympathetic nervous activity and insulin resistance. Masuo et al reported that significant weight loss resulted in significant amelioration on renal function following suppression on sympathetic activation and hyperinsulinemia (insulin resistance) [Masuo, et al 2012]. The findings suggest that strong linkage between sympathetic nervous activity, insulin resistance and renal function.…”

“…NE, plasma norepinephrine levels; Fat, total body fat-mass; SBP, systolic blood pressure; DBP, diastolic blood pressure; HOMA, homeostasis model of assessment of insulin resistance. [Masuo, et al 2012] Figure 2. When significant changes were observed comparisons between a calorie restricted diet vs. mild exercise alone vs. combination with diet + exercise over 24 weeks Very recently, Masuo et al [Masuo, et al 2012} showed the differences in mechanisms of weight loss-induced blood pressure reductions with neurohormonal parameters changes over 24 weeks with loss regimens (Figure 2).…”

“…[Masuo, et al 2012] Figure 2. When significant changes were observed comparisons between a calorie restricted diet vs. mild exercise alone vs. combination with diet + exercise over 24 weeks Very recently, Masuo et al [Masuo, et al 2012} showed the differences in mechanisms of weight loss-induced blood pressure reductions with neurohormonal parameters changes over 24 weeks with loss regimens (Figure 2). A calorie restricted diet caused suppression/normalization of sympathetic activation measured with plasma norepinephrine levels followed by improvements of insulin resistance, whereas exercise improved insulin resistance followed by normalization of norepinephrine levels.…”

Lifestyle Modification Is the First Line Treatment for Type 2 Diabetes

“…Weight loss treated with lifestyle modification including calorie restriction and/or exercise causes normalization of stimulated RAAS, sympathetic activation, insulin resistance, and hyperleptinemia, which are usually observed in type 2 diabetes and obesity. Recently, Straznicky et al [4] and Masuo et al [5] have shown the low caloric diet and exercise have different effects on insulin resistance, the RAAS, and sympathetic nervous activity in obese hypertensive subjects, although similar weight loss was observed between both interventions. Straznicky et al [4] reported that exercise had stronger effects of normalized the RAAS stimulation, sympathetic activation and insulin resistance compared to diet only, whereas Masuo et al [5] showed mild calorie restriction and mild exercise has different mechanisms on weight loss (normalization on sympathetic activation for mild calorie restriction, and normalization on insulin resistance for exercise).…”

“…Recently, Straznicky et al [4] and Masuo et al [5] have shown the low caloric diet and exercise have different effects on insulin resistance, the RAAS, and sympathetic nervous activity in obese hypertensive subjects, although similar weight loss was observed between both interventions. Straznicky et al [4] reported that exercise had stronger effects of normalized the RAAS stimulation, sympathetic activation and insulin resistance compared to diet only, whereas Masuo et al [5] showed mild calorie restriction and mild exercise has different mechanisms on weight loss (normalization on sympathetic activation for mild calorie restriction, and normalization on insulin resistance for exercise). The observations, however, demonstrate that a combination therapy for weight loss with a low caloric diet and exercise is recommended for weight loss due to stronger suppression of insulin resistance and sympathetic activation, which both are known as strong risk factors for cardiovascular events.…”