Association of Adolescents' Body Mass Index Classification With Preventive Clinical Care Receipt

PURPOSE

To examine differences in screening and advising for modifiable risk behaviors during well-visits based on adolescents' body mass index categories.

METHODS

Retrospective analyses were conducted with the National Institute of Health's NEXT Generation Health Study data, a nationally representative cohort of 10th graders. In wave 1 (2010), adolescents were classified as being underweight (<4.99th percentile), normal-weight (5-84.99th percentile), overweight (85-94.99th percentile), or with obesity (≥95th percentile) based on the body mass index categories described by the Centers for Disease Control and Prevention. In wave 2 (2011), adolescents were asked by their provider about smoking, alcohol use, use of other drugs, sexual activity, nutrition, and exercise, and whether they were advised about risks associated with these behaviors.

RESULTS

The sample consisted of 1,639 eligible participants as follows: 57.8% females, 63.3% 16-year-olds, 47.8% non-Hispanic Whites, 41.5% living in the South, 75.4% with health insurance, and 29.8% with low family affluence. Screening rates for overweight compared to normal-weight males were 51% reduced for smoking, 46% for alcohol use, 47% for other drug use, 57% for nutrition, and 47% for exercise. Screening rates were 40% reduced for other drug use for males with obesity, and 89% reduced for alcohol use for underweight males compared to normal-weight males. Advice receipt for females with obesity compared to normal-weight females was 90% increased for nutrition and 78% increased for exercise.

DISCUSSION

Overweight male adolescents reported being less likely to be screened across almost all preventive service topics representing missed opportunities for care delivery.

Screen time behaviours may interact with obesity genes, independent of physical activity, to influence adolescent BMI in an ethnically diverse cohort

BACKGROUND

There has been little investigation of gene-by-environment interactions related to sedentary behaviour, a risk factor for obesity defined as leisure screen time (ST; i.e. television, video and computer games).

OBJECTIVE

To test the hypothesis that limiting ST use attenuates the genetic predisposition to increased body mass index (BMI), independent of physical activity.

DESIGN

Using 7642 wave II participants of the National Longitudinal Study of Adolescent Health, (Add Health; mean = 16.4 years, 52.6% female), we assessed the interaction of ST (h week(-1) ) and 41 established obesity single nucleotide polymorphisms (SNPs) with age- and sex-specific BMI Z-scores in 4788 European-American (EA), 1612 African-American (AA) and 1242 Hispanic American (HA) adolescents.

RESULTS

Nominally significant SNP*ST interaction were found for FLJ35779 in EA, GNPDA2 in AA and none in HA (EA: beta [SE] = 0.016[0.007]), AA: beta [SE] = 0.016[0.011]) per 7 h week(-1) ST and one risk allele in relation to BMI Z-score.

CONCLUSIONS

While for two established BMI loci, we find evidence that high levels of ST exacerbate the influence of obesity susceptibility variants on body mass; overall, we do not find strong evidence for interactions between the majority of established obesity loci. However, future studies with larger sample sizes, or that may build on our current study and the growing published literature, are clearly warranted.