Longitudinal changes of blood pressure after weight loss: factors involved.

Background: The combination of obesity and hypertension (HT) places patients at a higher risk for adverse cardiovascular outcomes and raises the need to establish the pathogenic mechanisms of this relationship. The aim of this study was to assess the effects of important weight loss on longitudinal changes in blood pressure (BP) and investigate the pathogenic factors associated with these changes.

Methods: We performed a prospective, open-label study including 37 obese hypertensive patients (28 females, mean age 52±8 yr) undergoing BS. Before BS, and at 4 and 12 months postoperatively, the body mass index (BMI), 24-h ambulatory BP, renin-angiotensin-aldosterone system (RAAS: plasma rennin activity, aldosterone, angiotensin II, and angiotensin converting enzyme), sympathetic nervous system (SNS: metanephrines, normetanephrines, and norepinephrine) components, leptin, insulin, and abdominal fat were measured.

Results: Before BS, HT-duration was 6±6 years, the BMI 45±5 kg/m2 and excess weight (EBW) was 53±12 kg. At 12 months, the excess BMI loss was 14 kg/m2 and the EBW loss was 70 %; HT remission was observed in 70%; 24-h (systolic 19±13/diastolic 7±9 mm Hg), day and night BP levels and aldosterone, norepinephrine, leptin, insulin, subcutaneous and visceral abdominal fat (VAT) significantly decreased (P<.05). Mixed models for repeated measures revealed that HT-duration, baseline BP, BMI, and VAT area were the main variables associated with longitudinal changes in BP.

Conclusion: These results demonstrate that the hypotensive response after weight loss in severely hypertensive obese patients is mainly regulated by HT-duration, baseline BP, BMI and VAT area, independently of suppression of hyperinsulinemia or changes in RAAS and SNS components.