Researchers from The George Institute for Global Health at the University of Sydney reported that BMI can be a predictor of developing end-stage renal disease among patients with type 2 diabetes.

The findings, reported in Nutrition and Diabetes, are part of the results from the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified-Release Controlled Evaluation (ADVANCE) study.

“Most reported observational studies have found positive associations between being overweight or obese and kidney outcomes (which include development of [chronic kidney disease] CKD, rapid changes in kidney function or [end-stage renal disease] ESRD),” Kamel Mohammedi, MD, PhD, of the George Institute for Global Health at the University of Sydney, and colleagues wrote. “However, few have been large enough to compare people with and without diabetes reliably, and there remains some uncertainty in people with diabetes as to whether higher body mass index increases risk of developing microalbuminuria, and whether BMI-CKD associations are mediated through differences in renal risk factors affected by adiposity.”

Researchers reviewed data for 10,537 patients with type 2 diabetes. Participants were grouped into one of the following BMI categories:

  • 18.5 kg/m2 to 24 kg/m2 (normal weight, n = 2,894);
  • 25 kg/m2 to 29 kg/m2 (overweight, n = 4,340);
  • 30 kg/m2 to 34 kg/m2 (obesity grade 1, n = 2,265);
  • 35 kg/m2 to 39 kg/m2 (obesity grade 2, n = 744); and
  • 40 kg/m2 or greater (obesity grade 3, n = 294).

Researchers identified “major renal event” as developing a new case of microalbuminuria, doubling of creatinine, and/or ESRD or death due to kidney disease.

After 5 years of follow-up, major renal events occurred in 5% of patients with normal weight; in 4.2% of overweight patients, in 4.2% of patients categorized with obesity grade 1, in 5.8% of patients with obesity grade 2; and in 7.8% of patients with obesity grade 3.

ESRD occurred in 487 (4.6%) patients, but the risk increased with a higher BMI. Multivariable-adjusted HRs compared to normal weight, were:

  • 0.91 for being overweight;
  • 1.03 for obesity grade 1;
  • 1.42 for obesity grade 2; and
  • 2.16 for obesity grade 3.

“These findings were similar across subgroups by randomized interventions (intensive versus standard glucose control and perindopril-indapamide versus placebo),” the authors wrote. “Every additional unit of BMI over 25 kg/m2 increased the risk of major renal events by 4 (1-6)%. Comparable results were observed with the risk of secondary endpoints.”

The authors added, “Our findings encourage weight loss to improve nephroprotection in these patients.” – by Mark Neumann

Reference:
Mohammedi K, et al. Nutr Diabetes.2018;doi:10.1038/s41387-017-0012-y.

Disclosures: Mohammedi reports he has received personal fees from Novo Nordisk. Please see the full study for a list of all other authors’ relevant financial disclosures.