Diabetes and hypertension in severe obesity and effects of gastric bypass-induced weight loss

Abstract

Objective: To evaluate the preoperative relationships of hypertension and diabetes mellitus in severe obesity and the effects of gastric bypass (GBP)-induced weight loss.

Summary background data: Severe obesity is associated with multiple comorbidities, particularly hypertension and type 2 diabetes mellitus, that may affect life expectancy.

Methods: The database of patients who had undergone GBP by one general surgeon at a university hospital between September 1981 and January 2000 was queried as to weight, body mass index (BMI), pre- and postoperative diabetes, hypertension, and other comorbidities, including sleep apnea, hypoventilation, gastroesophageal reflux, degenerative joint disease, urinary incontinence, venous stasis, and pseudotumor cerebri.

Results: Of 1,025 patients treated, 15% had type 2 diabetes mellitus and 51% had hypertension. Of those with diabetes, 75% also had hypertension. There was a progressive increase in age between patients who had neither diabetes nor hypertension, either diabetes or hypertension, or both diabetes and hypertension. At 1 year after GBP (91% follow-up), patients lost 66 +/- 18% excess weight (%EWL) or 35 +/- 9% of their initial weight (%WL). Hypertension resolved in 69% and diabetes in 83%. Patients who resolved their hypertension or diabetes had greater %EWL and %WL than those who did not. African-American patients had a higher risk of hypertension than whites before GBP and were less likely to correct their hypertension after GBP. There was significant resolution of other obesity comorbidity problems. At 5 to 7 years after GBP (50% follow-up), %EWL was 59 +/- 24 and %WL was 31 +/- 13; resolution of hypertension was 66% and diabetes 86%.

Conclusions: These data suggest that type 2 diabetes mellitus and hypertension may be indirectly related to each other through the effects of obesity, but not directly as to cause and effect. The longer a person remains severely obese, the more likely he or she is to develop diabetes, hypertension, or both. GBP-induced weight loss is effective in correcting diabetes, hypertension, and other comorbidities but is related to the %EWL achieved. Severely obese African-Americans were more likely to have hypertension and respond less well to GBP surgery than whites. These data suggest that GBP surgery for severe obesity should be provided earlier to patients to prevent the development of diabetes and hypertension and their complications.