Obesity increasing in type 1 diabetes, associated with higher risk for chronic kidney disease

Obesity is increasing in people with type 1 diabetes and is associated with risk of chronic kidney disease (CKD), a study found.

Researchers studied all patients with type 1 diabetes in a regional health system in central and northeastern Pennsylvania to evaluate trends in obesity (body mass index ≥30 kg/m²), low estimated glomerular filtration rate (eGFR) (≤60 mL/min/1.73 m²), and albuminuria (urine albumin-to-creatinine ratio ≥30 mg/g) from 2004 to 2018, as well as the independent association of obesity with CKD in 2018. For comparison, they also looked at these trends in patients with type 2 diabetes in the same health system during the same time period and in 47,611 nondiabetic people from the general U.S. population who participated in the National Health and Nutrition Examination Survey from 1999 to 2018. Results were published Jan. 26 by the Journal of Clinical Endocrinology & Metabolism.

Overall, 4,060 patients with type 1 diabetes and 135,458 patients with type 2 diabetes had at least one visit at the health system during the study period. People with type 1 diabetes were younger than those with type 2 (median age, 39 vs. 62 years) at study entry. Obesity increased in patients with type 1 diabetes over time (32.6% in 2004 to 36.8% in 2018) but remained stable at about 60% in those with type 2 (crude prevalence, 58.1% in 2004 and 61.6% in 2018). Obesity was associated with increased odds of low eGFR in both type 1 and type 2 diabetes (adjusted odds ratios [ORs], 1.52 [95% CI, 1.12 to 2.08] and 1.29 [95% CI, 1.23 to 1.35], respectively).

Crude prevalence of low eGFR was relatively stable over time in patients with type 1 diabetes (17.5% in 2004 and 16.1% in 2018) and was higher than in the general U.S. population but lower than in patients with type 2 diabetes (17.5% vs. 5.7% vs. 26.6% in 2004, respectively). After adjustment for differences in age, sex, and race, however, the prevalence was highest in adults with type 1 diabetes. Similarly, the prevalence of albuminuria was highest in the type 1 diabetes population after adjustment. In the U.S. population, prevalence of both low eGFR and albuminuria were low and remained stable over time.

The authors noted that obesity, once considered rare in adults with type 1 diabetes, has now reached general population prevalence and that increased survival in this group increases the likelihood that many will progress to end-stage kidney disease or require kidney replacement. Several medications have been shown to prevent or slow kidney disease in adults with and without type 2 diabetes, but adults with type 1 diabetes have been excluded from most of these trials, the authors stated.

“Regardless, the increase in obesity among T1D [type 1 diabetes] is concerning for the future kidney health of these patients,” the authors wrote. “Our results highlight the importance of routine screening for kidney disease, particularly in adults with T1D and perhaps especially in those with obesity.” They also called for additional studies on the risks and benefits of treatments to reduce obesity and protect the kidneys in this population.