Effects of weight loss induced by gastric surgery on left ventricular mass and blood pressure in severe obese patients

Abstract

To assess the effects of weight loss induced by bariatric surgery on left ventricular mass (LVM), 24-hour blood pressure profile, and metabolic parameters in obese patients. Before and 6 months after a bariatric surgery for weight loss, echocardiography to assess the LVM and 24-hour ambulatory blood pressure monitoring (ABPM) were performed in 27 obese patients, 24 females / 3 males, body mass index (BMI) = 50,7 ± 6,1 Kg/ m2. Hemoglobin, serum albumin, glucose, lipid profile and liver enzymes levels were determined before and 6 months after surgery. BMI was significantly reduced from 50,7 ± 6,1 Kg/ m2 to 38,1 ± 3,3 Kg/ m2 (31,5% of the initial weight; p < 0.001). Left ventricular mass reduced from 201 ± 58,2 to 176 ± 60,6 g or 12,5 %; p < 0,01. Also the mean systolic blood pressure (SBP) (from 124 ± 10,2 to 113 ± 12,6 mmHg; p<0,001) and the mean diastolic blood pressure (DBP) (from 72,5 ± 7,7 to 68,9 ± 8,41mmHg; p< 0,03) were reduced. The percentage SBP fall during sleep did not change (-8.0±5.0 to -8.7±4.2%). There were no correlations between the changes in LVM and the changes in weight loss, SBP and DBP. Significant reductions were observed in blood glucose (from 96.8±26.3 to 78.1± 12.5 mg/dl; p<0,01), total- cholesterol (from 217.2±55.2 to 201.2± 55.0 mg/dl; p<0,01), and LDL-cholesterol (from 165.3±9 8.0 to 125.7± 46.5 mg/dl; p<0,02) but not in triglycerides levels (from 142.6± 99.7 to 124.2±80.2; p>0,05). HDL-cholesterol was significantly increased (from 42.8±8.3 to 50.6±12.7; p<0,01). Serum hemoglobin (13.2±1.7 vs 12.8±1.9 g/dl; p>0,05) and serum albumin (3.8± 0.3 vs 3.9± 0.3 g/dl; p>0,05) were not changed while alkaline phosphatase, but no other liver enzymes, increased significantly after surgery from144.0± 84.3 to 213 ± 57,9 g/dl; p=0,02.Concluding, bariatric surgery induced significant weight loss, decreases in LVM and 24h-ABPM, glucose, total-cholesterol and LDL-cholesterol levels and increases in HDL-cholesterol without changes in hemoglobin or albumin levels. The increase in alkaline phosphatase levels is probably caused by the higher lipolisis rate after surgery. The absence of correlations between weight loss or BP levels and LVM reduction suggests that other factors, possibly reductions in body fluid volume may account for LV changes.