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August 25, 2015
Prevention of Obesity in Infancy and Early Childhood: A National Institutes of Health Workshop
Addressing the childhood obesity epidemic continues to be a challenge. Given that once obesity develops it is likely to persist, there has been an increasing focus on prevention at earlier stages of the life course. Research to develop and implement effective prevention and intervention strategies in the first 2 years after birth has been limited. In fall 2013, the National Institute of Diabetes and Digestive and Kidney Diseases convened a multidisciplinary workshop to summarize the current state of knowledge regarding the prevention of infant and early childhood obesity and to identify research gaps and opportunities. The questions addressed included (1) “What is known regarding risk for excess weight gain in infancy and early childhood?” (2) “What is known regarding interventions that are promising or have been shown to be efficacious?” and (3) “What are the challenges and opportunities in implementing and evaluating behavioral interventions for parents and other caregivers and their young children?”
Childhood obesity is a public health problem of global significance. The medical and psychosocial comorbidities of childhood obesity are extensive, and the disorder is costly to individual children and societies. Particularly challenging is the “tracking” of obesity1: obese children tend to become obese adolescents, who in turn tend to become obese adults and harbor its many comorbidities. Although this certainly is not true of all obese children, environmental and biological pressures can undermine successful weight loss even among the most determined families. For these reasons, the prevention of childhood obesity is an international priority. However, controlled intervention trials striving to prevent childhood obesity are scarce, and even rarer are those occurring in the first 2 years of life. This presents an important opportunity for innovative early obesity prevention studies, guided by recent discoveries of biological and behavioral mechanisms.
In this context, the 2013 conference hosted by the National Institute of Diabetes and Digestive and Kidney Diseases on infancy and early obesity prevention was an important event. The resulting working group report was published in the May 2015 issue of JAMA Pediatrics.2 The report summarized what is currently known about obesity prevention in infancy and early childhood. Knowledge gaps and research needs were identified, including the need to better understand how obesity is influenced by infant weight and length (and how these relate to reference standards), infant body composition, intrauterine factors, rapid weight gain in infancy, physical activity, sleep, feeding modality (eg, bottle vs alteration in milk flow), food preferences and appetitive behavior in infants, formula and breast milk composition, complementary feeding, social cognitive variables (eg, parent or sibling behaviors), behavioral phenotypes (eg, food preferences, temperament), infant emotion and behavioral regulation, maternal feeding values and beliefs, and emerging risk factors (eg, hormonal milieu, microbiome).
The report by Lumeng et al2 will stimulate new multidisciplinary research that has not been explored to date. As this process unfolds, a natural partner for collaborative research will be primary care pediatrics—ie, pediatricians, family practice physicians, nurses, and other health professionals at the clinic. (These professionals also work in many school clinics.) Primary care clinicians have long-standing relations with children, are on the front line with families, and are the authority to whom parents turn so often for guidance. Moreover, primary care is rapidly becoming a pivotal repository for “big data” collection about patients—ie, electronic medical records (EMRs). For this and other reasons, primary care clinicians should be considered invested stakeholders in advancing the research agenda of the National Institutes of Health (NIH) working group.
As the NIH develops a strategy for investigating childhood obesity, how can primary care clinicians contribute? The overall research effort should capitalize on interventions that can already be implemented by primary care clinicians. A recent review of primary care interventions for childhood obesity dispels the notion that this intervention is not effective. Overweight or obese children treated in a primary care setting or with help from a primary health care professional showed significant improvements compared with controls for anthropometric, metabolic, and behavioral outcomes.3 Studies of primary care interventions for obesity, in general, are limited by small sample sizes, lack follow-up assessment, and differ in methodological rigor, highlighting the need for further research.
Results from a family-based behavioral intervention conducted at 4 large urban/suburban practices in New York are encouraging, with 105 families randomized to treatment.4 Children assigned to receive family intervention compared with control achieved significantly greater reductions in percentage over body mass index (%OBMI) at 3 months (P < .01) and 6 months (P < .001); %OBMI was calculated by [(child’s actual BMI minus BMI at the 50th percentile)/BMI at the 50th percentile] × 100. Model-adjusted mean (SD) %OBMI for the intervention group was 30.6 (9.7), 26.0 (9.9), and 24.2 (10.1) at 0, 3, and 6 months, respectively, compared with 30.5 (9.3), 28.7 (9.4), and 28.3 (9.5) for the control group. Moreover, parents in the intervention compared with control group showed significantly greater reductions in BMI over 6 months (P < .001). Model-adjusted mean (SD) BMI for parents in the intervention group was 36.7 (1.3) and 34.6 (1.4) at 0 and 6 months, respectively, compared with 36.7 (1.3) and 36.1 (1.3) for the control group (BMI is calculated as weight in kilograms divided by height in meters squared).
More recent evidence supports the efficacy of primary care–based intervention for pediatric obesity prevention. A recent cluster-randomized design examined 139 obese-prone children who were 8 to 12 years of age and recruited from 11 practices.5Families received either a single-behavior change intervention (ie, targeting sugar-sweetened beverages), multiple-behavior change intervention (ie, comprehensive diet and physical activity program), or a bullying prevention control intervention. Children in both active treatments compared with control showed significantly greater reductions in the primary outcome, BMI z score, over 12 months (P = .03). Specifically, the mean (SD) BMI z score change for the intervention group was −0.06 (0.28) compared with 0.01 (0.21) for the control group. In secondary analyses, children in the active treatments compared with control showed a greater reduction in total body weight (mean difference, −1.44 kg), although the difference was not significant (P = .095). Although longer-term follow-up was not assessed, these findings are encouraging for potential prevention efforts in pediatric primary care, perhaps even during the first 2 years of life.
Electronic medical record technology is becoming increasingly prevalent across health care systems in the nation. This presents novel opportunities to test scalable interventions that can bolster reach and the effect of early prevention studies. Electronic medical records can facilitate pediatrician identification of obese-prone infants for recruitment into clinical trials. Potential study participants could be identified by early anthropometrics (eg, weight-for-length percentiles) or associated trajectories (eg, rapid weight gain). These youth could then be targeted for recruitment from many different clinics, if not an entire health care network. This is feasible because EMRs have been used to facilitate recruitment into studies of older children.5,6
Electronic medical records may also serve as a platform to implement a standardized intervention protocol across entire primary care networks, which can bolster sample sizes and the diversity of participants. This was done in the Study of Technology to Accelerate Research (STAR) investigation, a cluster randomized design implemented at 14 clinics affiliated with a multispecialty group practice in Massachusetts. A total of 549 obese children aged 6 to 12 years participated in this study, which used electronic decision support for pediatricians at the point of care with children.7
It is time to critically evaluate and reassess8 the portfolio of research and clinical opportunities for primary care clinicians in early obesity prevention research. The pediatric primary care community can be a powerful force to advance the NIH workshop recommendations. Researchers should explore new collaborations that leverage the talents of primary care partners and take into consideration their real-life challenges when involved in studies of obesity prevention. Researchers and clinicians should work together to advance the science of obesity research so that findings can ultimately have a meaningful clinical benefit. When investigators come knocking at the clinic door for collaboration, they can be met with a greeting: “The doctor is in!”