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Shah P, Brady T, Meyers K, O’Shaughnessy M, Gibson K, Srivastava T, Zee J, Cattran D, Tuttle K, Gadegbeku C, Glenn D, Derebail V, Smith A, Wang C, Gillespie B, Bitzer M, Sethna C: Association of Obesity with Cardiovascular Risk Factors and Kidney Disease Outcomes in Primary Proteinuric Glomerulopathies. Nephron DOI 10.1159/000513869
Obesity is a well-established modifiable risk factor for cardiovascular disease (CVD) in the general population. However, the role of obesity for CVD risk is not well studied in subjects with proteinuric primary glomerular disease.
Shah and colleagues utilized an extensive prospectively collected database including 541 subjects with proteinuric primary glomerular disease (mainly minimal change disease, membranous nephropathy, and focal segmental glomerulosclerosis lesions) from the Nephrotic Syndrome Study Network (NEPTUNE) in order to study associations of CVD risk factors and obesity in adults and children with glomerular disease. In adults, obesity (as assessed by BMI) was associated with hypertension and dyslipidemia and a lower likelihood of achieving a complete remission with treatment for the underlying disease. In children there was an association of obesity with hypertension but not dyslipidemia, but a lower likelihood of reaching complete remission was seen with obesity, similar to adults. Satin use was not recorded. No long-term CVD outcomes were analyzed due to the short follow-up, which averaged about 3 years.
The association of obesity with a lower likelihood of achieving a complete remission is novel but not explained. Many possibilities are discussed, but causality cannot be proven in an observational study of this nature. The use of BMI to determine “obesity” in edematous subjects is problematical but the authors make an attempt to separate weight gain from sodium retention and true adiposity. In a companion article in the same issue, Sandino et al. [1] provided an excellent overview of obesity-related glomerulopathy (ORG) which is worth reading. It seems doubtful to me that the existence of ORG confounded the study by Shah et al., although a few patients with a focal segmental glomerulosclerosis lesion might have had ORG.
Overall the study by Shah et al. highlights the possible effects of concomitant obesity on risk for CVD and poor outcomes in proteinuric primary glomerular disease, but the lack of long-term follow-up makes this connection a weak one, requiring additional studies for confirmation.
References
1. Sandino J, et al. Which patients with obesity are at risk for kidney disease? Nephron. 2021, in press.
