Adult‐type hypolactasia and calcium intake in polycystic ovary syndrome

Abstract

Adult-type hypolactasia (ATH) is related to lower calcium and milk intake, which might be associated with obesity and metabolic disturbances. Women with polycystic ovary syndrome (PCOS) frequently suffer from metabolic disturbances including central obesity. We aimed to examine the association of ATH and calcium intake with anthropometric, metabolic and endocrine parameters in a cohort of PCOS and control women. Metabolic, endocrine and anthropometric measurements and oral glucose tolerance tests were performed in 504 PCOS and 366 control women. Genotyping of ATH, defined by the -13910 variant of the MCM6 gene, was performed. Calcium intake was assessed by questionnaires. Adult-type hypolactasia was more prevalent in PCOS women (29·8%) than in controls (23·5%) (P = 0·040). PCOS women with ATH had higher waist-to-hip ratio (WHR) (0·80 [0·75-0·88] vs 0·78 [0·73-0·85], P = 0·046), glucose 2 h (5·28 [4·57-6·33] mmol/l vs 5·67 [4·68-6·78] mmol/l, P = 0·037), HbA1c (5·2 [5·0-5·4]%vs 5·1 [5·0-5·3]%, P = 0·009), parathyroid hormone (3·72(2·91-4·86] pmol/l vs 3·61 [2·94-4·63] pmol/l, P = 0·030) and Ferriman-Gallwey-Scores (FG Scores) (7 [3-12] vs 4 [1-9], P = 0·002) and lower 25(OH)D levels (54·4 [35·2-80·6] nmol/l vs 68·4 [49·7-89·4] nmol/l, P < 0·001) than PCOS women without ATH. The association of 25(OH)D and FG-Scores with ATH remained significant in age-, BMI- and WHR-adjusted analyses. PCOS women within the highest quartile of calcium intake had significantly lower testosterone (P = 0·023) and androstenedione (P = 0·032) and significantly higher high-density lipoprotein (HDL) levels (P = 0·035) than PCOS women with lower calcium intake. Our results indicate an association of ATH with PCOS susceptibility. Moreover, ATH might influence WHR, HbA1c and FG-Scores as well as 25(OH)D levels. Higher calcium intake was associated with lower androgens and higher HDL levels.