title: Associations of Vitamin D with Inter- and Intra-Muscular Adipose Tissue and Insulin Resistance in Women with and without Polycystic Ovary Syndrome.
abstract: Low vitamin D and insulin resistance are common in polycystic ovary syndrome (PCOS) and associated with higher inter- and intra-muscular adipose tissue (IMAT). We investigated associations between vitamin D, IMAT and insulin resistance in a cross-sectional study of 40 women with PCOS and 30 women without PCOS, and pre- and post-exercise in a 12-week intervention in 16 overweight participants (10 with PCOS and six without PCOS). A non-classical body mass index (BMI) threshold was used to differentiate lean and overweight women (BMI ≥ 27 kg/m²). Measurements included plasma 25-hydroxyvitamin D (25OHD), insulin resistance (glucose infusion rate (GIR; mg/m²/min), fasting glucose and insulin, and glycated haemoglobin), visceral fat, mid-thigh IMAT (computed tomography) and total body fat (dual-energy X-ray absorptiometry). Women with both PCOS and low 25OHD levels had the lowest GIR (allp< 0.05). Higher IMAT was associated with lower 25OHD (B = -3.95; 95% CI -6.86, -1.05) and GIR (B = -21.3; 95% CI -37.16, -5.44) in women with PCOS. Overweight women with pre-exercise 25OHD ≥30 nmol/L had significant increases in GIR, and decreases in total and visceral fat (allp< 0.044), but no associations were observed when stratified by PCOS status. Women with PCOS and low 25OHD levels have increased insulin resistance which may be partly explained by higher IMAT. Higher pre-training 25OHD levels may enhance exercise-induced changes in body composition and insulin resistance in overweight women.
authors.affiliation: Department of Medicine, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton 3168, Victoria, Australia. david.scott@monash.edu.|Melbourne Medical School (Western Campus) and Australian Institute of Musculoskeletal Science, The University of Melbourne and Western Health, St Albans 3021, Victoria, Australia. david.scott@monash.edu.
authors.forename: David
authors.initials: D
authors.lastname: Scott
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. anju.joham@monash.edu.|Diabetes and Vascular Medicine Unit, Monash Health, Clayton 3168, Victoria, Australia. anju.joham@monash.edu.
authors.forename: Anju
authors.initials: A
authors.lastname: Joham
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. helena.teede@monash.edu.|Diabetes and Vascular Medicine Unit, Monash Health, Clayton 3168, Victoria, Australia. helena.teede@monash.edu.
authors.forename: Helena
authors.initials: H
authors.lastname: Teede
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. melanie.gibson@monash.edu.
authors.forename: Melanie
authors.initials: M
authors.lastname: Gibson-Helm
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. cheryce.harrison@monash.edu.
authors.forename: Cheryce
authors.initials: C
authors.lastname: Harrison
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. samantha.cassar@vu.edu.au.|Institute of Sport Exercise and Active Living, Victoria University, Melbourne 8001, Victoria, Australia. samantha.cassar@vu.edu.au.
authors.forename: Samantha
authors.initials: S
authors.lastname: Cassar
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. sammyhutch@hotmail.com.|Diabetes and Vascular Medicine Unit, Monash Health, Clayton 3168, Victoria, Australia. sammyhutch@hotmail.com.
authors.forename: Samantha
authors.initials: S
authors.lastname: Hutchison
authors.affiliation: Department of Medicine, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton 3168, Victoria, Australia. peter.ebeling@monash.edu.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Ebeling
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. nigel.stepto@vu.edu.au.|Diabetes and Vascular Medicine Unit, Monash Health, Clayton 3168, Victoria, Australia. nigel.stepto@vu.edu.au.
authors.forename: Nigel
authors.initials: N
authors.lastname: Stepto
authors.affiliation: Monash Centre for Health Research and Implementation, School of Public Health and Preventive Medicine, Monash University, Clayton 3168, Victoria, Australia. barbora.decourten@monash.edu.|Diabetes and Vascular Medicine Unit, Monash Health, Clayton 3168, Victoria, Australia. barbora.decourten@monash.edu.
authors.forename: Barbora
authors.initials: B
authors.lastname: de Courten
mesh_terms: D000273:Adipose Tissue / Q000502:physiology*; D001823:Body Composition; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D050177:Overweight; D011085:Polycystic Ovary Syndrome / Q000378:metabolism*; D014807:Vitamin D / Q000097:blood*
chemical_list: D014807:Vitamin D
keywords: exercise; insulin resistance; intramuscular adipose tissue; obesity; polycystic ovary syndrome; vitamin D