Calcium-phosphate homeostasis and insulin resistance in men

• Published in: Nutrition, metabolism, and cardiovascular diseases Vol. 34; no. 2; pp. 353 - 359
• Main Authors: Carnevale, Vincenzo, Nieddu, Luciano, Scillitani, Alfredo, Tinti, Maria Giulia, Eller-Vainicher, Cristina, Cosso, Roberta, Rendina, Domenico, Falchetti, Alberto
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2024
• Subjects: alkaline phosphatase; blood serum; body mass index; Bone Density Conservation Agents; Calcium; Calcium Phosphates; Calcium, Dietary; Calcium/phosphate homeostasis; chlorides; Creatinine; Electrolyte renal handling; glucose; Homeostasis; Humans; Insulin; Insulin Resistance; Insulin sensitivity/resistance; Male; metabolism; nutrition; Parathyroid Hormone; Phosphates; potassium; sodium; urine; Electrolyte renal handling; Insulin sensitivity/resistance; Calcium/phosphate homeostasis
• ISSN: 0939-4753; 1590-3729; 1590-3729
• DOI: 10.1016/j.numecd.2023.08.020

Data on P homeostasis in insulin resistance (IR) are still conflicting. We investigated calcium-phosphate homeostasis parameters in men with/without IR. 177 volunteers (aged 61.62 ± 12.11), whose body mass index (BMI) was 29.97 ± 6.35, were studied. On fasting blood and spot urine samples, we measured serum creatinine, sodium (sNa), potassium (sK), chloride (sCl), calcium (sCa), phosphate (sP), alkaline phosphatase total activity (ALP), glucose, insulin, parathyroid hormone (PTH), 25-hydroxy-vitamin D [25(OH)D], and urinary electrolytes corrected for creatinine (uNa/Cr, uK/Cr, uCl/Cr, uCa/Cr, and uP/Cr). Through the QUICKI index, we separated subjects with (IR+, n = 68) or without (IR-, n = 109) IR, and their parameters were compared. Associations were assessed by age-adjusted partial correlation, whose coefficients were compared by Fisher's transform. IR + had higher sP (3.54 ± 0.65 vs. 3.35 ± 0.47, p = 0.044) and lower uCa/Cr levels (0.073 ± 0.056 vs. 0.095 ± 0.072, p = 0.047) than IR-. BMI correlated with sP (r = 0.21, p < 0.05) and PTH (r = 0.29, p < 0.01). QUICKI negatively correlated with sCa (r = −0.22, p < 0.05) and positively with uCa/Cr (r = 0.21, p < 0.05), in turn correlating with uNa/Cr (r = 0.45, p < 0.001). In both groups, uCa/Cr correlated with eGFR and uNa/Cr (p < 0.05 to p < 0.001). In IR + only, sP correlated with BMI, PTH with insulin, and uP/Cr (p < 0.05 for all). IR+ and IR-coefficients differed (p < 0.05 to p < 0.001) for the correlation of sP with BMI and of PTH with insulin and uP/Cr. The higher sP and lower uCa/Cr levels found in men with IR + suggest that IR could modulate calcium-phosphate homeostasis, likely by affecting their renal handling. •Men with insulin resistance (IR+) had higher sP and lower uCa/Cr than IR- ones.•In IR+ only, sP correlated with BMI, and PTH with insulin and uP/Cr.•QUICKI (index of insulin sensitivity) positively correlated with uCa/Cr.•The renal clearances of Ca and P significantly differed between IR+ and IR-.