Weight loss mitigates risks for microvascular complications in type 2 diabetes
Adults with type 2 diabetes who have an elevated BMI at diagnosis are at increased risk for microvascular complications, although the risk can be reduced with weight loss, according to a study published in Diabetologia.
“Our data revealed a positive association between pre-diagnosis BMI and total vascular complications,” Matthias B. Schulze, DrPH, head of the department of molecular epidemiology at the German Institute of Human Nutrition, and colleagues wrote. “The observed association was driven predominantly by microvascular complications, and this applied to both kidney disease and neuropathy. A decreased risk was observed for microvascular complications, kidney disease and neuropathy with BMI loss shortly after diabetes diagnosis.”
Researchers recruited 1,083 participants with incident type 2 diabetes (54.2% men; median age at diabetes diagnosis, 60.4 years) from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam, a prospective cohort study investigating the role of diet in chronic disease occurrence. Patients with cardiovascular disease or vascular complications prior to diabetes diagnosis were excluded. In May 2014, physicians treating the participants were contacted to submit data on diabetes-related microvascular and macrovascular complications from medical records. Weight was self-reported through follow-up questionnaires. Pre-diagnosis weight was extracted from the most recent EPIC-Potsdam questionnaire response before diagnosis, and post-diagnosis weight was the closest questionnaire response after diagnosis.
Of the study cohort, 85 macrovascular events and 347 total microvascular events were reported. In a model adjusted for age and sex, each 5 kg/m2 higher BMI was associated with an increased risk for total vascular complications (adjusted HR = 1.17; 95% CI, 1.05-1.3). The association did not change after adjusting for education, lifestyle and family health history. The risk for total microvascular complications also increased with each 5 kg/m2 of BMI (aHR = 1.21; 95% CI, 1.07-1.36). Each 5 kg/m2 also increased the risk for kidney disease (aHR = 1.39; 95% CI, 1.21-1.6) and neuropathy (aHR = 1.12; 95% CI, 0.96-1.31).
No association was observed for macrovascular complications. The researchers wrote that several factors could explain the lack of an association.
“First, individuals who are overweight or obese may be treated more intensively for dyslipidemia, hypertension or hyperglycemia than counterparts with a normal weight,” the researchers wrote. “Second, sarcopenia may be prevalent among older, leaner people with diabetes, which might predispose to a higher risk of CVD events. Third, suboptimal control for smoking status may lead to spurious results.”
After adjusting for age, sex and pre-diagnosis BMI, a 1% or greater reduction in BMI after diabetes diagnosis was associated with lower risk for total vascular complications compared with a stable BMI (aHR = 0.73; 95% CI, 0.58-0.94). A 1% or greater BMI reduction was also associated with decreased risk for microvascular complications (aHR = 0.62; 95% CI, 0.47-0.8), kidney disease (aHR = 0.57; 95% CI, 0.4-0.81) and neuropathy (aHR = 0.73; 95% CI, 0.52-1.03).
“Our study underpins the importance of weight management in preventing major diabetes-associated complications and the need for well-designed studies for macrovascular complications,” the researchers wrote.