Background and aims: The accumulation of fat increases the formation of lipid perox-ides, which are partly scavenged by alpha-tocopherol (a-TOH). Here, we aimed to investigate the associations... Show moreBackground and aims: The accumulation of fat increases the formation of lipid perox-ides, which are partly scavenged by alpha-tocopherol (a-TOH). Here, we aimed to investigate the associations between different measures of (abdominal) fat and levels of urinary a-TOH metab-olites in middle-aged individuals. Methods and results: In this cross-sectional analysis in the Netherlands Epidemiology of Obesity study (N Z 511, 53% women; mean [SD] age of 55 [6.1] years), serum a-TOH and a-TOH metab-olites from 24-h urine were measured as alpha-tocopheronolactone hydroquinone (a-TLHQ, oxidized) and alpha-carboxymethyl-hydroxychroman (a-CEHC, enzymatically converted) using liquid-chromatography-tandem mass spectrometry. Body mass index and total body fat were measured, and abdominal subcutaneous and visceral adipose tissue (aSAT and VAT) were as-sessed using magnetic resonance imaging. Using multivariable-adjusted linear regression ana -lyses, we analysed the associations of BMI, TBF, aSAT and VAT with levels of urinary a-TOH metabolites, adjusted for confounders. We observed no evidence for associations between body fat measures and serum a-TOH. Higher BMI and TBF were associated with lower urinary levels of TLHQ (0.95 [95%CI: 0.90, 1.00] and 0.94 [0.88, 1.01] times per SD, respectively) and with lower TLHQ relative to CEHC (0.93 [0.90, 0.98] and 0.93 [0.87, 0.98] times per SD, respectively). We observed similar associations for VAT (TLHQ: 0.94 [0.89, 0.99] times per SD), but not for aSAT. Conclusions: Opposite to our research hypothesis, higher abdominal adiposity was moderately associated with lower levels of oxidized a-TOH metabolites, which might reflect lower vitamin E antioxidative activity in individuals with higher abdominal fat instead. (c) 2021 The Author(s). Published by Elsevier B.V. on behalf of The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Show less
Rafiq, R.; Walschot, F.; Lips, P.; Lamb, H.J.; Roos, A. de; Rosendaal, F.R.; ... ; Mutsert, R. de 2019
Background & aims: Obesity is a well-established risk factor of vitamin D deficiency. However, it is unclear which fat deposit is most strongly related to serum 25-hydroxyvitamin D (25(OH)D)... Show moreBackground & aims: Obesity is a well-established risk factor of vitamin D deficiency. However, it is unclear which fat deposit is most strongly related to serum 25-hydroxyvitamin D (25(OH)D) concentrations. Our aim was to distinguish the specific contributions of total body fat (TBF), abdominal subcutaneous adipose tissue (aSAT), visceral adipose tissue (VAT) and hepatic fat on 25(OH)D concentrations.Methods: We performed a cross-sectional analysis of the Netherlands Epidemiology of Obesity study, a population-based cohort study. We used linear regression analyses to examine associations of TBF, aSAT, VAT (n = 2441) and hepatic fat (n = 1980) with 25(OH)D concentrations. Standardized values were used to compare the different fat deposits.Results: Mean (SD) age and 25(OH)D concentrations of the study population was 56 (6) years and 70.8 (24.2) nmol/L, respectively. TBF was inversely associated with 25(OH)D concentrations in women, but not in men. One percent higher TBF was associated with 0.40 nmol/L (95%CI: -0.67 to -0.13) lower 25(OH)D. aSAT was not associated with 25(OH)D concentrations. One cm 2 higher VAT was associated with 0.05 nmol/L (-0.09 to -0.02) lower 25(OH)D in men, and 0.06 nmol/L (-0.10 to -0.01) lower 25(OH)D in women. Hepatic fat was only associated with 25(OH)D in men. A tenfold increase in hepatic fat was associated with 6.21 nmol/L (-10.70 to -1.73) lower 25(OH)D. Regressions with standardized values showed VAT was most strongly related to 25(OH)D.Conclusions: In women, TBF and VAT were inversely related to 25(OH)D concentrations. In men, VAT and hepatic fat were inversely related to 25(OH)D concentrations. In both groups, VAT was most strongly associated with 25(OH)D concentrations. (C) 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved. Show less
