MILAN—First-degree relatives of CKD patients have a greater prevalence of CKD risk factors than the general population and should be screened for impaired renal function, two studies suggest.
One study, conducted in Argentina, was a cross-sectional survey of 2,998 first-degree adult relatives of patients with end-stage renal disease (ESRD). The relatives were screened in 30 dialysis clinics to determine the prevalence of CKD and cardiovascular risk factors. “We found that the prevalence of hypertension and obesity in first-degree relatives of dialysis patients was increased, as well as the prevalence of CKD,” reported Felipe Inserra, MD, from Fresenius Medical Care Argentina, in Buenos Aires.
The researchers identified CKD in 19% of the relatives, a prevalence greater than that found in Argentina’s general population (12%). The proportion of relatives with hypertensionor a BMI of 25 kg/m2 or more was also higher in the relatives than in the general population (39% vs. 34.7% and 61.4% vs. 49%, respectively). In addition, 68.4% of the relatives had a sedentary lifestyle compared with 46.2% of the general population.
Among the relatives, stage 1 CKD was identified in 7.7%, stage 2 in 5.1%, stage 3 in 5.6%, stage 4 in 0.3%, and stage 5 in 0.7%.
Relatives of ESRD patients represent a high-risk population that must be screened for CKD, the researchers concluded. “Referring screen-positive individuals for care might help reduce the epidemic increase of ESRD,” they wrote.
In the other study, Sanjay Kumar Agarwal, MD, and colleagues from the All India Institute of Medical Sciences, in New Delhi, screened for CKD-associated risk factors in 510 first-degree relatives of 123 patients with nondiabetic CKD. Of the 123 CKD patients, 4.9% already had at least one family member who had developed CKD.
Among the 510 first-degree relatives, 25 (4.9%), 198 (38.8%), 180 (35.2%), 17 (3.3%), and 1 (0.2%), had stage 1, 2, 3, 4, and 5 CKD, respectively.
“CKD and its risk factors had a familial clustering,” Dr. Agarwal concluded. “Targeted screening of individuals with family history of CKD identifies those with previously unrecognized and poorly controlled risk factors, which is a strategy for preventing the disease.”
The researchers identified a history of smoking in 12% and hypertension and diabetes in 27% and 4%, respectively. In addition, 10% had elevated serum uric acid levels (above 7 mg/dL) and 5% had proteinuria, hematuria, and/or pyuria.
On multivariate analysis, older age, female sex, increased serum creatinine, presence of proteinuria, and BMI greater than 30 were significantly associated with impaired estimated glomerular filtration rate (eGFR), defined as less than 90 mL/min/1.73 m2. Male gender, diastolic BP of 90 mm Hg or higher, and impaired eGFR were associated with increased serum uric acid level.