Centre Hospitalier Universitaire Sainte-Justine Research Center, University of Montreal, Montreal, Quebec, Canada2Department of Pediatrics, University of Montreal, Montreal, Quebec, Canada.
Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada4Department of Medicine, McGill University, Montreal, Quebec, Canada5Respiratory Epidemiology and Clinical Research Unit, McGill University Heal.
JAMA Pediatr. 2016 Mar;170(3):227-35. doi: 10.1001/jamapediatrics.2015.3909.
Despite extensive evidence showing that lifestyle habits play a critical role in preventing or delaying the onset of type 2 diabetes in adults, little is known regarding the impact of lifestyle habits on type 2 diabetes risk in childhood.
To assess whether adiposity, fitness, moderate-to-vigorous physical activity, and screen time predict insulin sensitivity or insulin secretion during a 2-year period in children with a family history of obesity.
DESIGN, SETTING, AND PARTICIPANTS: This is a prospective longitudinal cohort study of 630 children, having at least 1 obese parent, recruited from schools in Quebec, Canada, between July 2005 and December 2008 in the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort. Children were assessed at baseline (ages 8-10 years) and 2 years later. Fitness was measured by peak oxygen consumption, percentage of body fat (adiposity) by dual-energy x-ray absorptiometry, moderate-to-vigorous physical activity using accelerometry, and screen time by average daily hours of self-reported television, video game, or computer use. Regression models were adjusted for age, sex, season, and pubertal stage. The current analysis was completed in October 2015.
Insulin sensitivity was measured by the homeostatic model assessment of insulin resistance and an oral glucose tolerance test-based index (Matsuda insulin sensitivity index). Insulin secretion was measured using the area under the curve of insulin to glucose during the first 30 minutes of the oral glucose tolerance test and using the area under the curve of insulin to glucose over 2 hours.
Of 630 children evaluated at baseline (mean [SD] age, 9.6 [0.9] years; 54.4% male; 56.2% normal weight, 19.2% overweight, and 22.7% obese), 564 were evaluated at 2-year follow-up. Adiposity and changes in adiposity were the central predictors of insulin dynamics over time. Every additional 1% of body fat at ages 8 to 10 years decreased insulin sensitivity by 2.9% (95% CI, -3.3% to -2.5%; P < .001) and led to a 0.5% (95% CI, 0.09% to 0.8%; P = .02) increased requirement in the area under the curve of insulin to glucose during the first 30 minutes of the oral glucose tolerance test 2 years later. Higher levels of moderate-to-vigorous physical activity and lower screen time appear to be beneficial to insulin sensitivity in part through their effect on adiposity levels.
Adiposity plays a determining role in cardiometabolic health at a young age. Public health strategies that promote healthy body weight, notably physical activity, need to target school-aged and possibly younger children.
尽管有大量证据表明生活方式习惯在预防或延迟成年人 2 型糖尿病发病方面起着关键作用，但对于生活方式习惯对儿童 2 型糖尿病风险的影响知之甚少。
评估肥胖症家族史儿童在 2 年内体脂肪量、体能、中等到剧烈体力活动和屏幕时间是否可预测胰岛素敏感性或胰岛素分泌。
设计、地点和参与者：这是一项前瞻性纵向队列研究，纳入了 2005 年 7 月至 2008 年 12 月期间在加拿大魁北克省学校招募的 630 名儿童，这些儿童至少有一位肥胖的父母，他们参加了魁北克青少年脂肪和生活方式研究（QUALITY）队列。在基线（8-10 岁）和 2 年后对儿童进行评估。体能通过峰值耗氧量测量，体脂肪量（肥胖）通过双能 X 射线吸收法测量，中等到剧烈体力活动通过加速度计测量，屏幕时间通过自我报告的电视、视频游戏或计算机使用的平均每日小时数测量。回归模型根据年龄、性别、季节和青春期阶段进行了调整。当前分析于 2015 年 10 月完成。
胰岛素敏感性通过稳态模型评估的胰岛素抵抗和基于口服葡萄糖耐量试验的指数（Matsuda 胰岛素敏感性指数）进行测量。胰岛素分泌通过口服葡萄糖耐量试验最初 30 分钟内的胰岛素对血糖的曲线下面积和口服葡萄糖耐量试验后 2 小时内的胰岛素对血糖的曲线下面积进行测量。
在 630 名基线评估（平均[标准差]年龄 9.6[0.9]岁；54.4%为男性；56.2%为正常体重，19.2%超重，22.7%肥胖）的儿童中，有 564 名在 2 年随访时进行了评估。体脂肪量和体脂肪量的变化是随时间推移胰岛素动态变化的核心预测因素。8 至 10 岁时每增加 1%的体脂肪量，胰岛素敏感性降低 2.9%（95%CI，-3.3%至-2.5%；P<0.001），并且在 2 年后口服葡萄糖耐量试验最初 30 分钟内的胰岛素对血糖的曲线下面积增加 0.5%（95%CI，0.09%至 0.8%；P=0.02）。较高水平的中等到剧烈体力活动和较低的屏幕时间似乎对胰岛素敏感性有益，部分原因是它们对体脂肪水平的影响。
肥胖在儿童早期的心血管代谢健康中起着决定性作用。促进健康体重的公共卫生策略，特别是身体活动，需要针对学龄儿童甚至更年幼的儿童。
