Osteoporosis is a Predictive Factor for Nephrolithiasis in an Adult Free-Living Caucasian Population From Southern Italy: A Longitudinal Retrospective Study Based on a General Practice Database

Abstract

Osteoporosis and nephrolithiasis are common multifactorial disorders with high incidence and prevalence in the adult population worldwide. Both are associated with high morbidity and mortality if not correctly diagnosed and accurately treated. Nephrolithiasis is considered a risk factor for reduced bone mineral density. Aim of this retrospective longitudinal study was to evaluate if osteoporosis is a predictive factor for the nephrolithiasis occurrence. Free-living subjects referring to “COMEGEN” general practitioners cooperative operating in Naples, Southern Italy. Twelve thousand seven hundred ninety-four Caucasian subjects (12,165 female) who performed bone mineral density by dual-energy X-ray absorptiometry and have a negative personal history for nephrolithiasis. Subjects aged less than 40 years or with signs or symptoms suggestive of secondary osteoporosis were excluded from the study. In a mean lapse of time of 19.5 months, 516 subjects had an incident episode of nephrolithiasis. Subjects with osteoporosis had an increased risk of nephrolithiasis than subjects without osteoporosis (Hazard Ratio = 1.33, 95% Confidence Interval 1.01–1.74, p = 0.04). Free-living adult subjects over the age of 40 with idiopathic osteoporosis have an increased risk of incident nephrolithiasis, suggesting the advisability of appropriate investigation and treatment of the metabolic alterations predisposing to nephrolithiasis in patients with osteoporosis. The study protocol was approved by the ASL Napoli 1 Ethical Committee, protocol number 0018508/2018

Idiopathic Osteoporosis and Nephrolithiasis: Two Sides of the Same Coin?

“…[20]. We have recently conducted an epidemiological survey involving 12,165 women and 629 men in Southern Italy (mean age 69.3 ± 10.0 years) of whom 10,157 had a clinical diagnosis of idiopathic osteoporosis, showing that osteoporosis is associated with an increased risk of nephrolithiasis (hazard ratio = 1.33, 95% confidence interval 1.01 to 1.74, p < 0.05) after adjustment for age, sex, body mass index, treatment for osteoporosis and smoking habits [21].…”

Metabolic syndrome is not associated to an increased risk of low bone mineral density in men at risk for osteoporosis

“…The study results do not demonstrate a significant association between MetS and Op in free-living Caucasian men from Southern Italy undergoing to DXA for suspected Op. This study is part of the SIMON study protocol [ 11 , 12 ]. Within the SIMON protocol, we have recently performed a study aimed to evaluate the relationship between MetS and Op in free-living women at risk of osteoporosis, according to the Italian EAL [ 11 ].…”

“…Within the SIMON protocol, we have recently performed a study aimed to evaluate the relationship between MetS and Op in free-living women at risk of osteoporosis, according to the Italian EAL [ 11 ]. Both men and women enrolled in the SIMON study live in the same geographic area and were enrolled in the same time laps [ 11 , 12 ]. Unlike what was observed in SIMON men, a significant association between MetS and Op was observed among SIMON women [ 11 ].…”

“…The SIMON study protocol has been extensively previously described [ 11 , 12 ]. Briefly, the SIMON database is constituted by the medical records of 180,724 patients referring to the general practitioners (GPs) registered to the “COMEGEN” Medical Cooperative on June 1, 2018.…”

“…In this regard, the Italian National Health Service (Sistema Sanitario Nazionale in Italian, SSN) proposes (i) the BMD assessment via DXA to all women and men of any age with an Op major risk factor, and in postmenopausal women and men over the age of 60 years with at least three or more Op minor risk factors, and (ii) the global cardiovascular risk assessment by determination of all MetS constitutive elements to all women and men over the age of 39 years [ 9 , 10 ]. The SIMON (SIndrome Metabolica, Osteoporosi e Nefrolitiasi in Italian; metabolic syndrome, osteoporosis and nephrolithiasis) study is an epidemiological survey based on administrative data performed in Naples, Southern Italy, to estimate the relationship occurring between all these frequent and multifactorial disorders [ 11 , 12 ]. Thanks to the SIMON study protocol, we have recently demonstrated a significant association between Op and MetS in free-living Caucasian women referred to DXA for suspected Op [ 11 ].…”