CVD, cancer, depression influence kidney disease risk in diabetes
A long-term follow-up of Australian adults with diabetes suggests the age-adjusted incidence rate of chronic kidney disease was six new cases per 100 person-years during a span of 11 years, with comorbidities such as cardiovascular disease, cancer, obesity and depression all driving the higher risk for renal function decline, according to findings published in Diabetes Care.
“A range of factors were independently associated with developing kidney disease in this large community-based study of more than 9,000 people with diabetes, including expected factors like age, duration of diabetes, existing kidney function, obesity and high blood pressure,” Louisa Sukkar, MD, MBBS, FRACP, a doctoral student and clinical nephrologist at The George Institute for Global Health in Camperdown, New South Wales, Australia, told Healio. “Some previously unrecognized factors increased the risk for developing kidney disease, including cardiovascular disease, cancer and depression/anxiety. Unlike studies in other settings, markers of socioeconomic status were not associated with developing kidney disease in the Australian universal payer health system. However, geographic residence was associated with developing kidney disease, with higher rates outside the major cities.”
In a prospective study, Sukkar and colleagues analyzed data from 9,313 adults with diabetes aged at least 45 years participating in EXTEND45, a population-based cohort study conducted between 2006 and 2014 (mean age, 65 years; 55% men). Researchers linked data from the Sax Institute’s 45 and Up study cohort with community laboratory and administrative data in New South Wales, Australia. Primary outcome was the first estimated glomerular filtration rate measurement of less than 60 mL/min/1.73 m2 recorded during follow-up. Participants with an eGFR less than 60 mL/min/1.73 m2 at baseline were excluded. Researchers used Poisson regression analyses to estimate the incidence of developing an eGFR of less than 60 mL/min/1.73 m2 and Cox regression analysis to examine factors associated with the study outcome.
Role of age, demographics
Within the cohort, 54.8% had prevalent diabetes and 45.2% developed incident diabetes during follow-up.
During a median follow-up of 5.7 years, 2,106 adults (22.6%) developed incident eGFR of less than 60 mL/min/1.73 m2, for an incidence rate of six per 100 person-years (95% CI, 5.7-6.3).
Researchers found that the incidence rate of renal decline was higher among older adults, increasing from 1.5 per 100 person-years among adults aged 45 to 54 years to 26 per 100 person-years among adults aged at least 85 years. The risk for developing incident eGFR of less than 60 mL/min/1.73 m2 rose by 23% for each 5-year increase in age (HR = 1.23; 95% CI, 1.19-1.26), with results persisting after adjusting for sex.
Compared with living in a major city, adults who lived in an inner regional city were more likely to develop renal decline (HR = 1.14; 95% CI, 1.03-1.26), as were adults living in an outer regional city (HR = 1.36; 95% CI, 1.17-1.58).
Risk with comorbidities
Obesity status also played a role in renal function. Compared with adults with a normal-range BMI (< 24.9 kg/m²), adults with obesity class I were 32% more likely to develop an eGFR of less than 60 mL/min/1.73 m2 (HR = 1.32; 95% CI, 1.14-1.53), with risk rising to 44% for adults with obesity class III (HR = 1.44; 95% CI, 1.16-1.8). Other comorbidities that influenced the risk for renal decline were hypertension (HR = 1.52; 95% CI, 1.33-1.73), coronary heart disease (HR = 1.13; 95% CI, 1.02-1.24), cancer (HR = 1.3; 95% CI, 1.14-1.5), and depression or anxiety (HR = 1.14; 95% CI, 1.01-1.27), as did having diabetes for at least 5 years (HR = 1.37; 95% CI, 1.24-1.52).
Adults who had a higher baseline eGFR, had a partner or reported consuming 20 standard alcoholic drinks per week were less likely to develop a decline in renal function; however, researchers noted that sex, annual household income and smoking status were not predictors of declining renal function.
“All clinicians need to be looking for kidney disease among people with diabetes to maximize the opportunity to put in place measures to halt its progression and thus lessen the burden on individuals and the health system,” Sukkar said. “Implementation of research investigating innovative approaches to ensure routine screening for the detection of kidney disease is much needed to allow early for detection and thus earlier intervention strategies to be put in place.” – by Regina Schaffer
For more information:
Louisa Sukkar, MD, MBBS, FRACP, can be reached at The George Institute for Global Health, P.O. Box M201, Missenden Road, NSW 2050, Australia; email: firstname.lastname@example.org.
Disclosures: The EXTEND45 study is funded by research grants from Amgen, Eli Lilly and Merck. Sukkar reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.