Fat, adipokines, bone structure and bone regulatory factors associations in obesity

Abstract

Context: Obese adults (OB; BMI ≥30) have higher bone mineral density (BMD) and more favourable bone microarchitecture than normal weight adults (NW; BMI 18.5-24.9). Objective: To identify which fat compartments have the strongest association with bone density and bone turnover and whether biochemical factors (adipokines, hormones and bone regulators) are likely to be important mediators of the effect of obesity on bone. Design: Cross-sectional, observational, matched case-control study. Setting: Participants were recruited from the local community Participants: Two hundred healthy men and women aged 25-40 or 55-75 were recruited in individually-matched OB and NW pairs. Body composition, BMD and bone microarchitecture were determined by dual energy X-ray absorptiometry (DXA), computed tomography (CT) and high resolution peripheral computed tomography (HR-pQCT). Bone turnover and potential regulators such as C-terminal cross-linking telopeptide (CTX), type 1 procollagen N-terminal peptide (PINP), sclerostin, periostin, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), insulin like growth factor 1 (IGF-1), adiponectin, leptin and insulin were assessed. Main outcome: Planned exploratory analysis of the relationships between fat compartments, areal and volumetric BMD, bone microarchitecture, bone turnover markers and bone regulators. Results: Compared with NW, OB had lower CTX, PINP, adiponectin, IGF-1, and 25OHD and higher leptin, PTH and insulin (all p<0.05). CTX and subcutaneous adipose tissue (SAT) were the bone marker and fat compartment most consistently associated with areal and volumetric BMD. In regression models, SAT was negatively associated with CTX (p<0.001). When leptin was added to the model, SAT was no longer associated with CTX, but leptin (p<0.05) was negatively associated with CTX. Conclusions: SAT is associated with lower bone resorption and properties favourable for bone strength in obesity. Leptin may be an important mediator of the effects of SAT on the skeleton.

Association of vitamin D levels with anthropometric and adiposity indicators across all age groups: a systematic review of epidemiologic studies

“…Our systematic search identified 42 cross-sectional studies ( 12 , 13 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 79 , 83 , 84 , 85 ) and two cohort investigations ( 60 , 78 ) (with 33,815 participants) that investigated the potential relationship between 25(OH)D serum concentrations and anthropometric/adiposity indices in adults and/or elderly population. The studies about the link between 25(OH)D serum level and anthropometric indices in adults and/or elderly population were carried out in the following countries: 9 studies from USA, 3 from UK, 3 from Spain, 2 from Turkey, 4 from Saudi Arabia, 2 from Iran, 2 from India, 2 from Italy, 2 from Germany, and 18 others from China, UAE, Pakistan, Australia, Finland, England, Portugal, Malaysia, Bulgaria, Austria, Canada, Denmark, Greece, New Zealand, and the Netherlands.…”

“…The age of participants was >18 years old. Among the included studies, 27 articles ( 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 84 , 85 ) involved both sexes, and 17 investigations conducted in females ( 12 , 13 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 ) and males ( 69 , 70 , 71 ) only. The included studies mostly considered the following potential confounders: age, sex, season of blood sampling, smoking, vitamin D status, body fat mess, weight, height, BMI, IGF-1, PTH, UVB, alcohol, tobacco, sports, use of multivitamin supplements, menopausal status/HRT use, physical activity, socioeconomic status, income, job, obesity, education level, lifestyle, sun exposure, lean mass, nutrient intake, residence type, race, ethnicity, serum calcium, magnesium and phosphate, GFR, 25(OH)D, CRP, WC, month of blood collection, marital status, district, area, latitude, phosphorus, serum alanine aminotransferase, creatinine, and IL-6.…”

“… NM The mean plasma 25(OH)D level was significantly lower in the obese group than in age-matched controls. 4 Vilaca ( 84 ), 2022 UK, NM Cross-sectional 200 F/M 25–40 or 55–75 Community-dwelling men and women from South Yorkshire Autoanalyzers NM Weight, height, BMI, body composition. Age, sex Compared with normal weight, obese individuals had lower 25(OH)D. 5 Avila Castillo ( 85 ), 2023 Germany, Caucasian Cross-sectional 1032 (533/499) F/M 40–79 Adult population of LIFE-Adult-Study Chemiluminescent enzyme immunometric assay Deficiency: 25(OH)D <20 ng/mL BMI, WC, HC, WHR, %BF.…”

“…Another cross-sectional investigation ( 84 ) among community-dwelling men and women reported that compared with normal weight, obese individuals had lower 25(OH)D levels ( P < 0.05).…”

Nutritional therapy bridges the critical cut-off point for the closed-loop role of type 2 diabetes and bone homeostasis: A narrative review

“…T2DM is associated with obesity, which raises the issue of skeletal frailty in T2DM due to obesity factors. T Vilaca et al reported that obesity-promoted bone mass accumulation was associated with enhanced bone mechanical loading and cytokine or hormone secretion [ 62 ], consistent with patients with T2DM exhibiting normal or high BMD but did not reduce their fracture risk [ 12 ]. At present, weight loss is still one of the nutritional treatment goals for overweight/obese T2DM patients to improve glycemic control and reduce the risk of cardiovascular morbidity [ 57 ].…”