Role of weight loss and polyunsaturated fatty acids in improving metabolicfitness in moderately obese, moderately hypertensive subjects

Objective While the exact regulatory interactions between blood pressure (B P) and obesity are not completely understood, weight loss provides an alter native to pharmacological treatment of hypertension. The intent of this rep eated measures study of mild-moderate hypertensive, moderately obese subjec ts (34 females/18 males) was to determine if the reduction in BP following weight loss could be further affected by modifying the fatty acid (FA) comp osition of the hypocaloric diet. Methods BP, insulin sensitivity (Si), and lipid parameters were assessed be fore and after a 10-week calorie-restricted period. Subjects were randomize d to one of three dietary groups differing in FA composition. Reduced body weight was maintained for a further 4 weeks and body composition assessment , BP and heart rate measurements were repeated. Results Weight loss (10%) in obese hypertensive subjects resulted in substa ntial improvements in BP, Si and lipid profile. There was no additional eff ect on the reduction in BP by the type of FA consumed in the diet Following weight loss, there was a trend for omega-3 FAs to have a protective effect on fat-free mass loss (compared to omega-6 FA Group and saturated FA Group ) and a trend to further enhance Si. There were significant improvements in circulating lipid profiles independent of the dietary FA intervention foll owing the weight loss. The improvements in BP and body composition were mai ntained during the weight-loss maintenance period. The type of fat consumed had minor differential effects on some of the measured metabolic outcomes. Conclusion These results provide strong support for modest weight loss as a treatment for hypertension. (C) 2001 Lippincott Williams & Wilkins.