Nephrolithiasis, bone mineral density, osteoporosis, and fractures: a systematic review and comparative meta-analysis

Summary: Our meta-analysis demonstrates that people with nephrolithiasis have decreased bone mineral density, an increased odds of osteoporosis, and potentially an elevated risk of fractures. Introduction: People with nephrolithiasis might be at risk of reduced bone mineral density (BMD) and fractures, but the data is equivocal. We conducted a meta-analysis to investigate if patients with nephrolithiasis have worse bone health outcomes (BMD), osteoporosis, and fractures versus healthy controls (HCs). Methods: Two investigators searched major databases for articles reporting BMD (expressed as g/cm2 or a T- or Z-score), osteoporosis or fractures in a sample of people with nephrolithiasis, and HCs. Standardized mean differences (SMDs), 95 % confidence intervals (CIs) were calculated for BMD parameters; in addition odds (ORs) for case-control and adjusted hazard ratios (HRs) in longitudinal studies for categorical variables were calculated. Results: From 1816 initial hits, 28 studies were included. A meta-analysis of case-control studies including 1595 patients with nephrolithiasis (mean age 41.1 years) versus 3402 HCs (mean age 40.2 years) was conducted. Patients with nephrolithiasis showed significant lower T-scores values for the spine (seven studies; SMD = −0.69; 95 % CI = −0.86 to −0.52; I2 = 0 %), total hip (seven studies; SMD = −0.82; 95 % CI = −1.11 to −0.52; I2 = 72 %), and femoral neck (six studies; SMD = −0.67; 95 % CI = −−1.00 to −0.34; I2 = 69 %). A meta-analysis of the case-controlled studies suggests that people with nephrolithiasis are at increased risk of fractures (OR = 1.15, 95 % CI = 1.12–1.17, p < 0.0001, studies = 4), while the risk of fractures in two longitudinal studies demonstrated trend level significance (HR = 1.31, 95 % CI = 0.95–1.62). People with nephrolithiasis were four times more likely to have osteoporosis than HCs (OR = 4.12, p < 0.0001). Conclusions: Nephrolithiasis is associated with lower BMD, an increased risk of osteoporosis, and possibly, fractures. Future screening/preventative interventions targeting bone health might be indicated. © 2016, International Osteoporosis Foundation and National Osteoporosis Foundation.