Incidence and correlation of metabolic syndrome and kidney stones in a healthy screening population

BACKGROUND: To study the incidence of metabolic syndrome (MetS) and kidney stones in a healthy screening population and to explore the correlation between them. METHODS: The physical examination data of 11,827 people screened at the First Affiliated Hospital of Soochow University from August 2019 to July 2020 were analyzed. MetS diagnostic criteria were based on the 2004 guidelines of Chinese Diabetes Society (CDS). Multivariate logistic regression was used to analyze the correlation between MetS and various characteristics and kidney stones. Trend analysis was represented by P value, and P<0.05 indicated statistical significance. RESULTS: The present study comprised 6,570 males (55.6%, aged 46.15±13.653 years) and 5,257 females (44.4%, aged 41.41±11.712 years). Of these, 1,036 (8.8%) had kidney stones and 1,552 (13.1%) had MetS. Among the MetS patients, 35.1% had a body mass index (BMI) ≥25, 27.7% had hypertension, 10.8% had hyperglycemia, and 31.2% had dyslipidemia. Kidney stone morbidity was 14.5% in the MetS group and 7.9% in the non-MetS group (P<0.05). As the number of MetS characteristics increased, kidney stone morbidity showed a linear increasing trend (P<0.05 for trend). With an increase in BMI and blood triglycerides (TG), and a decrease in lipoprotein cholesterol (HDL-C), the incidence of kidney stones had an increasing trend (P<0.05 for trend). Sex, age and MetS were independent risk factors for the occurrence of kidney stones, with and odds ratio (OR) of 1.493 [95% confidence interval (CI): 1.264–1.763] for MetS. Of the MetS characteristics, BMI ≥25 and blood pressure (BP) ≥140/90 mmHg were independent risk factors for kidney stones, with OR values of 1.209 (95% CI: 1.047–1.396) and 1.248 (95% CI: 1.071–1.453), respectively. CONCLUSIONS: MetS is an independent risk factor for kidney stones. Appropriate medication and dietary advice may help to correct urinary metabolic abnormalities and prevent the recurrence of kidney stones.