The correlation of metabolic and renal biomarkers with vitamin D status in postmenopausal women

Abstract

Background: To our knowledge, the mutual involvement of a variety of metabolic and renal biomarkers and vitamin D (determined as 25-hydroxyvitamin D [25(OH)D]) in postmenopausal women has not been examined yet. Therefore, we aimed to explore such a relationship by a thorough statistical multimarker approach. Methods: A total of 150 (diabetes and cardiovascular disease-free) postmenopausal women were included. Anthropometric and biochemical parameters were measured. The fatty liver index (FLI) and Homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. Univariate and multivariate binary logistic regression analyses were used to test the predictions of cardiometabolic markers for [25(OH)D] status. Principal component analysis (PCA) was applied to explore the effect of examined biomarkers on [25(OH)D] status. Results: Univariate binary regression analysis revealed positive associations between FLI and [25(OH)D] [OR=1.036 (1.020–1.052), P<0.001] and HOMA-IR with [25(OH)D] [OR=2.385 (1.601–3.551), P<0.001]. Multivariate logistic regression analysis with backward selection enabled us to find the best model consisted of two markers, i.e. FLI [OR=1.032 (1.016–1.048), P<0.001] and glucose [OR=2.167 (1.001–4.693), P=0.050] associated with the first tertile of [25(OH)D]. PCA extracted 2 significant factors: Renal function-related factor and Metabolic syndrome-related factor. Renal function-related factor [i.e. creatinine, uric acid, retinol-binding protein 4 (RBP4) and cystatin C] explained 29% of the variance. Also, Metabolic syndrome-related factor (i.e. HOMA-IR, FLI, hsCRP and fibrinogen) explained 29% of the variance of the tested parameters. Moreover, binary logistic regression analysis revealed significant positive predictive ability of both factors, i.e. Renal function-related factor and Metabolic syndrome-related factor (P=0.044 and P<0.001, respectively) towards [25(OH)D] status. Conclusion: The joint involvement of renal function biomarkers and metabolic syndrome-related features (i.e. insulin resistance, inflammation and non-alcoholic fatty liver disease) can differentiate postmenopausal women with lower [25(OH)D] levels from other women.

Uvod: Prema našem saznanju zajednički uticaj različitih metaboličkih i renalnih biomarkera na nivo vitamin D (odre|enog kao 25-hidroksivitamin D [25(OH)D]) kod žena u postmenopauzi još uvijek nije ispitivan. Stoga je cilj istraživanja bio da se ispita povezanost ovih biomarkera primenom temeljne statističke analize koja uključuje više navedenih biomarkera. Metode: Ukupno 150 žena u postmenopauzi (koje nemaju dijabetes, ni kardiovaskularna oboljenja) je uključeno u istraživanje. Mereni su antropometrijski i biohemijski parametri. Indeks masne jetre (FLI) i indeks insulinske rezistencije (HOMA-IR) su izračunati. Univarijantna i multivarijantna binarna logistička regresija su primenjene da bi se odredili kardiometabolički prediktori nivoa [25(OH)D]. Rezultati: Univarijantna binarna regresiona analiza je pokazala pozitivnu korelaciju izme|u FLI i [25(OH)D] [OR=1.036 (1.020–1.052), P<0,001] i HOMA-IR sa [25(OH)D] [OR=2.385 (1.601–3.551), P<0,001]. Multivarijantna logistička regresiona analiza je pokazala najbolji model sa 2 markera, tj. FLI [OR=1.032 (1.016– 1.048), P<0,001] i glukoza [OR=2.167 (1.001–4.693), P=0,050] koji su korelirali sa prvom tercilom vrednosti [25(OH)D]. PCA je izdvojila 2 značajna faktora: Renal function-related faktor i Metabolic syndrome-related faktor. Renal function-related faktor [tj. kreatinin, mokraćna kiselina, retinolvezujui protein 4 (RBP4) i cistatin C] su objasnili 29% varijanse. Takođe, Metabolic syndrome- related faktor (tj. HOMA-IR, FLI, hsCRP i fibrinogen) su objasnili 29% varijanse ispitivanih parametara. štaviše, binarna logistička regresiona analiza je pokazala pozitivnu prediktivnu sposobnost oba faktora, tj. Renal function- related faktora i Metabolic syndrome-related faktora (P=0,044 i P<0,001) za nivo [25(OH)D]. Zaključak: Zajedničko dejstvo renalnih biomarkera i markera metaboličkog sindroma (tj. insulinska rezistencija, inflamacija i nealkoholna steatoza jetre) mogu diferencirati žene u postmenopauzi sa nižim nivoom [25(OH)D] u odnosu na ostale žene.