Dipartimento di Medicina Clinica e Chirurgia, Unit of Endocrinology, Federico II University Medical School of Naples, Via Sergio Pansini 5, 80131 Naples, Italy.
Centro Italiano per la cura e il Benessere del paziente con Obesità (C.I.B.O), Department of Clinical Medicine and Surgery, Endocrinology Unit, University Medical School of Naples, Via Sergio Pansini 5, 80131 Naples, Italy.
Nutrients. 2020 Apr 17;12(4):1132. doi: 10.3390/nu12041132.
Prader-Willi syndrome (PWS) is a genetic disorder characterized by hyperphagia with progressive, severe obesity, and an increased risk of obesity-related comorbidities in adult life. Although low dietary vitamin D intake and low 25-hydroxy vitamin D (25OHD) levels are commonly reported in PWS in the context of bone metabolism, the association of low 25OHD levels with fat mass has not been extensively evaluated in PWS adults. The aims of this study were to investigate the following in PWS adults: (1) 25OHD levels and the dietary vitamin D intake; (2) associations among 25OHD levels with anthropometric measurements and fat mass; (3) specific cut-off values for body mass index (BMI) and fat mass predictive of the 25OHD levels. In this cross-sectional, single-center study we enrolled 30 participants, 15 PWS adults (age 19-41 years and 40% males) and 15 control subjects matched by age, sex, and BMI from the same geographical area (latitude 40° 49' N; elevation 17 m). Fat mass was assessed using a bioelectrical impedance analysis (BIA) phase-sensitive system. The 25OHD levels were determined by a direct competitive chemiluminescence immunoassay. Dietary vitamin D intake data was collected by three-day food records. The 25OHD levels in the PWS adults were constantly lower across all categories of BMI and fat mass compared with their obese counterpart. The 25OHD levels were negatively associated with BMI ( = 0.04), waist circumference ( = 0.03), fat mass ( = 0.04), and dietary vitamin D intake ( < 0.001). During multiple regression analysis, dietary vitamin D intake was entered at the first step ( < 0.001), thus explaining 84% of 25OHD level variability. The threshold values of BMI and fat mass predicting the lowest decrease in the 25OHD levels were found at BMI ≥ 42 kg/m ( = 0.01) and fat mass ≥ 42 Kg ( = 0.003). In conclusion, our data indicate that: (i) 25OHD levels and dietary vitamin D intake were lower in PWS adults than in the control, independent of body fat differences; (ii) 25OHD levels were inversely associated with BMI, waist circumference, and fat mass, but low dietary vitamin D intake was the major determinant of low vitamin D status in these patients; (iii) sample-specific cut-off values of BMI and fat mass might help to predict risks of the lowest 25OHD level decreases in PWS adults. The presence of trained nutritionists in the integrated care teams of PWS adults is strongly suggested in order to provide an accurate nutritional assessment and tailored vitamin D supplementations.
普拉德-威利综合征（PWS）是一种遗传疾病，其特征为多食症，逐渐出现严重肥胖，并增加成年后患肥胖相关合并症的风险。尽管在骨代谢背景下，PWS 患者通常存在低膳食维生素 D 摄入和低 25-羟维生素 D（25OHD）水平，但低 25OHD 水平与脂肪量之间的关联尚未在 PWS 成人中得到广泛评估。本研究旨在调查以下内容：（1）25OHD 水平和膳食维生素 D 摄入；（2）25OHD 水平与人体测量学和脂肪量之间的关系；（3）预测 25OHD 水平的特定 BMI 和脂肪量的截断值。在这项横断面、单中心研究中，我们纳入了 30 名参与者，包括 15 名 PWS 成人（年龄 19-41 岁，40%为男性）和 15 名在同一地理区域（纬度 40°49'N；海拔 17 米）按年龄、性别和 BMI 匹配的对照组。脂肪量使用生物电阻抗分析（BIA）相敏系统进行评估。25OHD 水平通过直接竞争化学发光免疫测定法确定。通过三天的食物记录收集膳食维生素 D 摄入数据。与肥胖对照组相比，PWS 成人的 BMI 和脂肪量各个类别中的 25OHD 水平均持续较低。25OHD 水平与 BMI（ = 0.04）、腰围（ = 0.03）、脂肪量（ = 0.04）和膳食维生素 D 摄入（ < 0.001）呈负相关。在多元回归分析中，维生素 D 摄入在第一步中被输入（ < 0.001），从而解释了 25OHD 水平变化的 84%。预测 25OHD 水平最低降低的 BMI 和脂肪量的阈值值为 BMI≥42kg/m（ = 0.01）和脂肪量≥42kg（ = 0.003）。总之，我们的数据表明：（i）与对照组相比，PWS 成人的 25OHD 水平和膳食维生素 D 摄入较低，这与体脂差异无关；（ii）25OHD 水平与 BMI、腰围和脂肪量呈负相关，但低膳食维生素 D 摄入是这些患者维生素 D 状态低下的主要决定因素；（iii）特定的 BMI 和脂肪量样本截断值可能有助于预测 PWS 成人中 25OHD 水平最低降低的风险。建议在 PWS 成人的综合护理团队中配备训练有素的营养师，以提供准确的营养评估和针对性的维生素 D 补充。
