How effective are weight loss and exercise to reduce High BP?
Weight loss and exercise are integral for hypertension control. Americans are increasingly becoming more sedentary and overweight. According to the latest NHANES data, 36.3% of adult American aged ≥20 years are obese: 34.3% of men are obese, while 38.3% of women are obese. African American women are at particularly high risk, as nearly 57% are obese. Obesity predisposes patients to become hypertensive. Weight loss through exercise improves hypertension because exercise improves antioxidant effects and reduces systemic vascular resistance. The PREMIER trial showed that intensive lifestyle modification, entailing a low-sodium DASH diet, weight loss, and exercise, is successful in lowering blood pressure in patients with pressures 120 to 159/80 to 95 mm Hg. The average improvement, from baseline, was –4.3/–2.6 mm Hg. Two meta-analyses showed that approximately 1 kg in weight loss translates to approximately 1 mm Hg improvement in systolic blood pressure. Physicians should keep in mind that obesity itself is a risk factor for chronic kidney disease, as it can cause glomerular hyperfiltration and proteinuria. A recent meta-analysis found that weight loss reduces proteinuria and systolic blood pressure (∼8 mm Hg for nonsurgical interventions [e.g., diet, exercise, or medications] and ∼23 mm Hg for surgical interventions [e.g., gastric bypass]). Glomerular hyperfiltration improved, with the GFR decreasing ∼25.6 mL/min, in those morbidly obese patients undergoing surgery, providing possible long-term kidney protection.
As the American population ages and more patients face chronic disease, expert opinion recognizes the importance of exercise to reduce cardiovascular events. Patients with chronic kidney disease are at high risk because this disease is an independent cardiovascular risk factor. Guidelines advocate that older patients perform moderate-intensity exercise (e.g., walking) for a minimum of 30 minutes 5 days weekly or vigorous activity (e.g., jogging) for a minimum of 20 minutes thrice weekly. In a small group of chronic kidney disease patients, regular exercise significantly reduced blood pressure. However, once these patients stopped their exercise training, their blood pressures promptly increased. A study of patients with chronic kidney disease undergoing cardiac rehabilitation showed improvements in weight, physical well-being, and lipid profiles. Finally, a study in which obese, chronic kidney disease patients underwent exercise training, dietary education, and orlistat therapy (a drug that reduces fat malabsorption) revealed that these patients can effectively lose weight. This is important because obesity is a barrier to transplantation, and transplantation provides a survival benefit to chronic kidney disease patients, as compared to dialysis, through reduction in cardiovascular risk.