The changing profile of patients with calcium nephrolithiasis and the ascendancy of overweight and obesity: a comparison of two patient series observed 25 years apart.

Background. Epidemiological data indicate an increasing incidence and prevalence of nephrolithiasis (NL) worldwide in the last few decades. Methods. The aim of this study was to compare the clinical and biochemical profiles of recurrent stone formers referred to a Kidney Stone Centre from March 1983 to June 1986 with the one featured by patients seen 25 years later in the same geographical area, Campania, southern Italy. Results. Idiopathic calcium stone formers made up the large majority of the patient population in both series. Those examined in 2008-11 showed higher age at the onset of NL, higher prevalence of overweight/obesity and higher urinary excretion of oxalate and phosphate compared with those seen in 1983-86. The differences in the urinary biochemical variables remained significant upon accounting for age, gender, creatinine clearance and body mass index (BMI), and were not observed in patients with primary hyperparathyroidism enrolled in the same periods. A greater prevalence of uric acid stone formers was also observed in the 2008-11 population. Conclusions. The massive epidemics of overweight/obesity and the substantial modifications of dietary habits over the last few decades in most Western countries may be the factors underlying the changing clinical and biochemical profiles of patients with recurrent NL.