Associations between lumbar bone mineral density, serum 25-hydroxyvitamin D and history of kidney stones in adults aged 30-69 years in the USA (NHANES 2011-2018)

Abstract

Objectives: Most kidney stones contain calcium, which is closely associated with human bone health. Therefore, we aimed to determine the relationship between the history of kidney stones and human bone health. This study examined the associations between lumbar bone mineral density (BMD), serum 25-hydroxyvitamin D (25-OHD) and a history of kidney stones in individuals aged between 30 years and 69 years.

Design and data analysis: A multivariate logistic regression model was used to estimate the relationship between lumbar BMD, serum 25-OHD levels and kidney stones in this cross-sectional study. All models incorporated survey sample weights and were adjusted for covariates.

Setting: National Health and Nutrition Examination Survey (NHANES) 2011-2018. The exposure and outcomes of this study included the lumbar BMD and presence of kidney stones.

Participants: All the 7500 participants for this cross-sectional survey were selected from the NHANES between 2011 and 2018.

Main outcome measures: The main outcome of this study was the presence of kidney stones. The interviewers asked the questions on kidney stones while the respondents were at home, using a computer-assisted personal interview system.

Results: Lumbar BMD was negatively correlated with a history of kidney stones in all three multivariate linear regression models; the negative association existed in all genders after adjusting for all confounding factors. In the multiple regression analysis, there was an interaction between serum 25-OHD and lumbar BMD (p<0.05) regarding the influence on kidney stones; the negative association between lumbar BMD and kidney stones was more obvious in the higher 25-OHD group (≥50 nmol/L).

Conclusion: The study results suggest that maintaining a high lumbar BMD may reduce the incidence of kidney stone formation. Simultaneously, maintaining a high serum 25-OHD level may be more beneficial in preventing the occurrence or recurrence of stones while ensuring a high lumbar BMD.

Keywords: urogynaecology; urolithiasis; urology.

Figure 1

Flowchart of sample selection from the NHANES 2011–2018. BMD, bone mineral density; NHANES, National Health and Nutrition Examination Survey; 25-OHD, 25-hydroxyvitamin D.

Figure 2

Association between lumbar BMD and history of kidney stones. Each black point represents a sample. The solid red line represents the smooth curve fit between variables. Blue bands represent the 95% CI from the fit. Gender, age, race, body mass index, education level, blood urea nitrogen, serum calcium, serum creatinine, serum glucose, serum phosphorus, serum sodium, physical activities, smoking behaviour, poverty to income ratio, alkaline phosphatase, total cholesterol, total protein, serum uric acid, serum potassium, and serum triglycerides were adjusted. BMD, bone mineral density.