Racial divergence in adiposity during adolescence: The NHLBI growth and health study
Racial divergence in adiposity during adolescence: The NHLBI growth and health study
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DOI：
10.1542/peds.107.3.e34
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发表时间：
2001-03-01
期刊：
影响因子：
8
通讯作者：
Daniels, SR
中科院分区：
文献类型：
--
作者：
Kimm, SYS;Barton, BA;Daniels, SR
背景。黑人女性特别容易肥胖，其患病率为50%。心血管疾病、中风和糖尿病的高死亡率和发病率部分归因于他们的肥胖。近年来，一个特别令人关注的公共健康问题是，肥胖的长期趋势日益严重，种族差异甚至更大，特别是在女孩和妇女中。在20世纪60年代初至80年代末，6至11岁的黑人女孩的肥胖患病率增加了两倍，而白人女孩的肥胖患病率则增加了一倍。同样，12至17岁的青春期女孩超重和肥胖也有所增加，黑人青春期女孩的增幅更大。黑人女孩肥胖率的长期增长趋势预示着黑人女性未来潜在的严重慢性疾病负担，这一负担已经高于白人女性。非胰岛素依赖型糖尿病在儿童和青少年中发病率的增加，传统上被认为是成人发病的疾病，可能是目前美国青少年肥胖高发的结果。不出所料，这种情况在黑人青年中更为常见。青春期前的黑人女孩通常比同龄的白人女孩瘦，但到了20岁，黑人女性比白人女性要重得多。因此，假设肥胖的种族差异在青春期进化。然而，由于目前缺乏纵向队列数据，这种情况发生的具体年龄和潜在因素尚未确定。1985年，美国国家心肺血液研究所（NHLBI）发起了一项为期10年的纵向多中心研究（NHLBI生长与健康研究[NGHS]），调查黑人和白人女孩青春期肥胖的发展及其环境、社会心理和心血管疾病的相关风险因素。本报告的目的是在一个双种族女孩队列中研究青春期肥胖和体重增加的自然史，以调查肥胖的种族差异的演变，并研究肥胖增加与青春期成熟、能量摄入和身体活动之间的关系。参与者和设置。共有2379名9至10岁的黑人（51%）和白人（49%）女孩从加利福尼亚州里士满市和俄亥俄州辛辛那提市的公立和教会学校以及在华盛顿特区一个大型健康维护组织注册的家庭中招募。参与者资格仅限于宣布自己是黑人或白人的女孩及其父母，并且生活在种族和谐的家庭中。设计与统计分析。NGHS是一项针对黑人和白人女孩的多中心前瞻性研究，每年对9至10岁至18至19岁的女孩进行访问。在第10次年度随访时随访率为89%。用Holtain卡尺测量肱三头肌、髂上和肩胛下的皮褶。性成熟由训练有素的注册护士评估。每年通过问卷调查确定月经初潮的发生时间。所有临床评估均由经过中央培训的工作人员使用通用方案进行。使用纵向回归（广义估计方程）模型来检验肥胖与种族、年龄、青春期成熟度、每日能量摄入和身体活动之间的关系。主要结果测量。主要结局指标是肱三头肌、肩胛骨下和耻骨上部位的皮肤褶皱（SSF）的总和，作为两个种族之间比较的肥胖指标。身体质量指数（BMI；体重（公斤）除以身高（米）的平方）的分布按年龄和种族进行检查。SSF的种族差异在10岁时很明显，不考虑成熟因素。在每个实足年龄中，黑人女孩比白人女孩青春期成熟得更早的比例更高。SSF的第15个百分位数相似，并且在整个研究过程中保持不变。黑人女孩的SSF中位数虽然与9岁时白人女孩的SSF中位数相似，但在12岁时黑人女孩的SSF中位数变得更大（36mm对32.5 mm），在19岁时差异为6mm （49.5 mm对43.5 mm）。相比之下，黑人女孩在所有年龄段（9毫米和10毫米，或分别为18%和15%，9岁）的第85和第95百分位值的差异明显更高，这些种族差异随着年龄的增长而扩大（20毫米和26毫米，或分别为25%和24%，19岁）。在9岁至19岁之间，中位BMI的种族差异从0.4 kg/m增加到2.3 kg/m(2)。与SSF的第15百分位数不同，9岁黑人女孩的身体质量指数比白人高3%左右。与SSF一样，对于体重较重的女孩来说，黑人女孩在9岁时的体重指数在第85百分位时高出11%，到19岁时则高出23%。在10岁至18岁之间，第95百分位的BMI差异也从3.6 kg/m增加到8.1 kg/m(2)。在多元纵向回归模型中调整成熟阶段后，黑人女孩在12岁时的肥胖程度明显高于白人女孩。两组的肥胖增加最多的是在青春期，白人女孩的SSF大约增加了8.0毫米，黑人女孩增加了10.8毫米。肥胖增加的下一个里程碑发生在月经初潮前后，白人女孩SSF增加5.0毫米，黑人女孩SSF增加3.4毫米。此外，随着初潮的到来，肥胖的累积量也显著增加，即白人女孩每年增加3.7毫米，黑人女孩每年增加3.0毫米。虽然青春期对肥胖增加的影响在两种种族中是相似的，但就每个实际年龄而言，黑人女孩的肥胖累积量更大，因为她们比白人女孩早熟。能量摄入与肥胖增加呈显著负相关但与身体活动水平无关。体脂积累最多的时间发生在青春期的两个主要里程碑，即青春期和月经初潮的开始。即使在调整青春期成熟后，12岁以后，黑人女孩明显比白人女孩胖。对于两个种族群体来说，月经初潮更早会增加肥胖的风险。因此，肥胖的初级预防应从促进年轻女孩在青春期开始成熟之前保持正常生长开始，因为肥胖增加与月经初潮提前有关。其次，更重要的是，在青春期发育的关键阶段，儿科医生应该特别警惕生长监测，这是肥胖大量积累的脆弱时期。需要更加重视黑人女孩的预防工作，以尽量减少她们在青春期肥胖的风险。
Background. Black women are particularly vulnerable to obesity, with a prevalence rate of >50%. The higher mortality and morbidity from cardiovascular disease, stroke, and diabetes have been attributed, in part, to their obesity. In recent years, a particular public health concern is the increasing secular trend in obesity with an even greater racial disparity, especially in girls and women. Between the early 1960s and late 1980s, the prevalence of obesity tripled in young black girls 6 to 11 years of age, while it doubled in white girls. Similarly, both overweight and obesity in adolescent girls 12 to 17 years of age also increased, with a greater increase again seen in adolescent black girls. This secular trend in obesity with a greater increase in black girls signals a potentially grave future chronic disease burden on black women, which is already higher than in white women. The increasing occurrence in children and adolescents of noninsulin-dependent diabetes, traditionally viewed as an adult-onset condition, may be a consequence of the currently high prevalence of obesity in American youth. Not surprisingly, this condition is seen more frequently among black youths.Prepubescent black girls are generally leaner than age-comparable white girls, but by 20 years of age, black women are considerably heavier than are white women. Thus, it is assumed that the racial disparity in adiposity evolves during adolescence. However, the specific age at which this occurs and underlying factors are yet to be identified because of the current paucity of longitudinal cohort data.Objectives. In 1985, the National Heart, Lung, and Blood Institute (NHLBI) initiated a 10-year longitudinal multicenter study (the NHLBI Growth and Health Study [NGHS]) to investigate the development of obesity in black and white girls during adolescence and its environmental, psychosocial, and cardiovascular disease risk factor correlates. The purpose of this report is to examine the natural history of adiposity and weight accretion during adolescence in a biracial cohort of girls to investigate the evolution of the racial divergence in adiposity and to examine the relationships between increases in adiposity and pubertal maturation, energy intake, and physical activity.Participants and Setting. A total of 2379 black (51%) and white (49%) girls, 9 to 10 years of age, were recruited from public and parochial schools in Richmond, California, and Cincinnati, Ohio, and from families enrolled in a large health maintenance organization in the Washington, DC area. Participant eligibility was limited to girls and their parents who declared themselves as being either black or white and who lived in racially concordant households.Design and Statistical Analysis. The NGHS is a multicenter prospective study of black and white girls with annual visits from 9 to 10 years of age through 18 to 19 years of age. The follow-up rate was 89% at the 10th annual visit. Skinfold measurements were obtained at the triceps, suprailiac, and subscapular sites with Holtain calipers. Sexual maturation was assessed by trained registered nurses. The onset of menarche was ascertained annually by questionnaire. All clinical assessments were conducted using a common protocol by centrally trained staff. Longitudinal regression (generalized estimating equations) models were used to examine the relationship between adiposity and race, age, pubertal maturation, daily energy intake, and physical activity.Main Outcome Measures. The main outcome measure was the sum of skinfolds (SSF) at the triceps, subscapular, and suprailiac sites as an index of adiposity for comparison between the 2 racial groups. Body mass index (BMI; weight in kilograms divided by height in meters, squared) distributions were examined by age and race.Results. Racial differences in SSF, unadjusted for maturation, were evident at 10 years of age. For each chronological age, there was a higher proportion of black girls with more advanced pubertal maturation than white girls. The 15th percentiles for SSF were similar and remained thus throughout the study. The median for SSF for black girls, although similar to the median SSF of white girls at 9 years of age, became greater for black girls at 12 years of age (36 mm vs 32.5 mm) and at age 19 years the difference was 6 mm (49.5 mm vs 43.5 mm). In contrast, the difference in the 85th as well as the 95th percentile values for SSF were substantially higher in black girls at all ages (9 mm and 10 mm, or 18% and 15%, respectively, at age 9 years) and these racial differences widened with age (20 mm and 26 mm, or 25% and 24%, respectively, by age 19 years).The racial difference in the median BMI increased from 0.4 to 2.3 kg/m(2) between ages 9 and 19 years. Unlike SSF at the 15th percentile, the BMI for lean 9-year-old black girls was similar to3% higher than whites. As with SSF, for heavier girls, BMI at the 85th percentile even at age 9 years was 11% greater in black girls and became 23% greater by age 19 years. Differences in BMI at the 95th percentile also increased from 3.6 to 8.1 kg/m(2) between ages 10 and 18 years.After adjusting for stages of maturation in multivariate longitudinal regression models, adiposity for black girls became significantly greater at age 12 years compared with white girls. The largest gain in adiposity for both groups was seen at the time of pubescence, an approximate increase of 8.0 mm in SSF for white girls and 10.8 mm for black girls. The next milestone for a gain in adiposity occurred around menarche with an increase in SSF of 5.0 mm for white girls and 3.4 mm for black girls. Additionally, there was a significantly greater accrual of adiposity with earlier achievement of menarche, ie, a gain of 3.7 mm for white girls and 3.0 mm for black girls for each year. Although the effect of puberty on the gain in adiposity was similar for both races, for each chronological age, there was a greater accrual of adiposity in black girls because they matured earlier than white girls. Energy intake was significantly and inversely associated with increasing adiposity but not with levels of physical activity.Conclusion. The time of the largest accrual of body fat occurred around the 2 major pubertal milestones, the onsets of puberty and menarche. Even after adjusting for pubertal maturation, after age 12 years, black girls were significantly fatter than were white girls. Earlier menarche conferred an additional risk for greater gain in adiposity for both racial groups. Primary prevention of obesity, therefore, should commence with fostering the maintenance of normal growth in young girls before the initiation of pubertal maturation because increased adiposity is associated with earlier menarche. Next, and more importantly, pediatricians should be particularly vigilant with growth monitoring during the critical milestones of pubertal development, a vulnerable time for a large accrual of adiposity. Greater emphasis needs to be placed on preventive efforts in black girls to minimize their risk for developing obesity during adolescence.