Evaluation and Management of Nephrolithiasis in the Aging Population With Chronic Kidney Disease

Anna L Zisman; Fredric L Coe; Elaine M Worcester


Aging Health. 2011;7(3):423-433. 

In This Article

Metabolic Characteristics of the Geriatric Stone Former

Few studies have specifically addressed the metabolic characteristics of the older patient with nephrolithiasis. In an important report, Gentle et al. reviewed the clinical records of 5942 stone patients treated at their institution and compared the clinical and metabolic characteristics of two patient groups: those 65 years and under and those older than 65 years of age.[21] The geriatric cohort (721 patients) comprised 12% of the total patient population and did not differ from the younger patient group in total previous stone episodes, rates of surgical interventions or disease burden. Statistically significant differences in serum metabolic parameters included a higher PTH level, lower 1,25-hydroxyvitamin D concentrations, higher creatinine concentrations, and higher glucose levels in the older cohort – all potentially consistent with an increased burden of CKD in the older group. Differences in the 24-h urinary parameters between groups included lower calcium, citrate, magnesium, phosphate, sodium, sulfate and uric acid excretions in the geriatric population. Measured creatinine clearances were significantly lower in the older group (70.2 vs 96.6 ml/min). No differences were noted in urine pH or urine volume. In the geriatric cohort, the most common abnormality was hypocitraturia (36%), followed by hypercalciuria (17%). In the younger cohort, the most common abnormality was hypercalciuria (30%), while hypocitraturia was seen in 27% of patients. The most common stone in the geriatric cohort was calcium oxalate (74%), followed by uric acid (11%) and calcium phosphate (6%). Mixed calcium oxalate and uric acid stones comprised 7% of the stones in the older stone formers. These rates are somewhat different from the younger cohort where calcium oxalate stones were noted in 84%, uric acid stones were seen in 5%, and calcium phosphate (4%) and mixed uric acid/calcium oxalate (7%) were similar to the older cohort. Though one might suspect that the increased rates of uric acid stones in the elderly would be due to differences in urine pH, the mean pHs were similar between groups (6.01 and 6.02), and the proportion of patients with pH less than 5.5 were also similar (32 vs 28% in the older and younger cohort, respectively). The number of patients affected by gout was also similar between groups (1.3 vs 1.5%).