In our multi-ethnic population sample, a non-intensive (~ 3 visits per year) weight management program that reinforced healthy dietary modifications and regular daily activity over a 4-year period resulted in a statistically significant reduction of BMI z-score and LDL-cholesterol, and improvement of glucose tolerance.
Extensive evidence previously published supports the effectiveness of intensive weight-loss programs in children. In a study conducted by Wilfley et al., 204 overweight children were enrolled to determine the short-term and long-term efficacy of weight-loss and weight maintenance programs . After 5 months of intensive weekly meetings focused on weight-loss treatment with a multi-disciplinary team, almost 90% of children exhibited a decreased BMI z-score. At the end of the weight-loss intervention, the 2 active maintenance groups experienced a mean change in BMI z-score of – 0.22 from baseline to 2-year follow-up versus the control group. Such BMI z-score reduction is similar to the one shown in our study by the end of the 4-year follow-up (−0.16); however, Wilfley et al. did not evaluate the impact of weight loss on metabolic parameters. Savoye et al. studied a population of 209 obese children to evaluate the effects of a 12-month weight management program on adiposity and metabolic parameters . The program included exercise, nutrition, and behavior modification: intervention occurred biweekly the first 6 months and bimonthly thereafter. At the end of study, the weight-management group experienced a significant decrease of BMI and HOMA-IR compared to the control group; conversely, no difference was found relative to changes in fasting glucose, HDL-cholesterol, LDL-cholesterol, or blood pressure. Reinehr et al. studied changes in weight status and cardiovascular disease (CVD) risk factors in 203 obese children who attended a 1-year outpatient intervention program; enrolled subjects were then evaluated 1 year after the end of the intervention . The program included weekly meetings with an exercise physiologist as well as once to twice monthly with a dietitian and a psychologist. Children who experienced a reduction of BMI SDS (72% of the group) at the end of the 12-month intervention maintained this reduction 1 year later. In addition, children with reduced BMI SDS (but not those without) showed improved HDL-cholesterol, LDL-cholesterol, blood pressure, and HOMA-IR.
Although the positive effects of all these studies were sustained for a relatively long period of time, the high costs associated with the frequent utilization of a team of dietitians, social workers, and exercise physiologists render this format not widely applicable. In contrast, our findings suggest that weight management programs based on less frequent encounters with a smaller team (pediatric nurse practitioner and a registered dietitian) may result in a similarly effective and lasting reduction of obesity and obesity-associated metabolic abnormalities.
The importance of preventing or reducing the severity of overweight in childhood is supported by a number of studies demonstrating the link between pediatric obesity and morbidity and mortality in adulthood. Three previous studies have identified an association between overweight in children and adolescents with increased rates of death due to coronary heart disease [21, 22] and with death from all causes [22, 23]. In a large cohort of American-Indian subjects followed since childhood , the rate of premature death (before 55 years of age) from endogenous causes among children in the highest quartile of BMI was more than double than that in children in the lowest quartile. Of note, the association between BMI and premature death was attenuated but remained significant after adjustment for glucose level, cholesterol level, and blood pressure: thus, some of the effects of overweight on the risk of premature death may not depend on abnormal glucose and lipid metabolism, or on hypertension.
In our cohort of 61 children, 5 were found with IGT at baseline; in 4 of these children, the OGTT normalized by the end of the 4-year follow-up period, while one child became diabetic. In a similar study, Weiss et al. identified 33 children with IGT in a population sample of 117 obese children . By the end of a 2-year period, 15 of those with IGT reverted to normal glucose tolerance while 8 developed Type 2 DM. When compared to those who reverted to normal glucose tolerance, subjects who developed DM were significantly more obese at baseline and increased their BMI during the follow-up period; in our study, the relationship between OGTT results and initial BMI z-score and/or change in BMI z-score overtime is less clear. While the association between IGT and risk to develop DM has not been well defined in children, it has been clearly demonstrated in adults [25, 26]; in addition, IGT in adults appears to be linked to an increased risk for cardiovascular disease and mortality [27, 28].
In the present study, 25 of the 60 subjects had dyslipidemia at the initial visit: by the end of the 4-year follow-up period, in 15 of these 25 subjects the abnormal lipid levels normalized: unlike those with persistently abnormal lipid panel, the 15 children with normalized lipid levels exhibited a significantly decreased BMI z-score during the 4-year follow-up period. Previous cross-sectional studies have shown a high prevalence of low HDL-cholesterol and elevated TG in obese children [29, 30]. A longitudinal study conducted in the United Kingdom in more than 5,000 children showed that 1 SD greater BMI at age 9–12 years was associated with high TG and low HDL-cholesterol at age 15–16 years ; in the same study, changing from overweight/obese at age 9–12 to normal weight at age 15–16 was associated with better cardiovascular risk profiles than remaining overweight/obese from childhood through adolescence. Data from 4 prospective cohorts have demonstrated that cardiovascular risk factors in childhood (including high TG) significantly predict subclinical atherosclerosis as early as 9 years of age , thus justifying sustained efforts to correct obesity and lipid abnormalities in children.
There are some limitations of our study, such as the lack of a control group and the relatively small sample size. However, the fact that our results are consistent with those of studies including a larger number of subjects and a control group supports the validity of our findings. In addition, there may have been a selection bias regarding the subjects included in the retrospective analysis, since only a small number of children initially evaluated at our Weight Management Center were eventually followed for 2 or more years. We can speculate that the effects of the program were less significant for those subjects followed for less than 2 years. Those subjects having a longer duration of follow-up may have experienced weight loss early in the program, greater adherence to the lifestyle changes, or more family involvement. Our results demonstrate that a non-intensive weight management program offers potential medical benefits to children and adolescents who are sufficiently motivated to continue their follow-up visits.
The long duration of our retrospective study, and the non-intensive approach of our intervention, has rendered unfeasible the concomitant evaluation of a control, completely untreated, group of obese children. To circumvent such limitation, we have used two historical control groups followed longitudinally by Reinehr et al.  and by D’Hondt et al. . In the former study, 100 overweight children [BMI-SDS 1.92 (1.27-2.75)] with a mean age of 9 years (6–15 years) were periodically evaluated during a 2-year period without any intervention. This control group did not experience any significant change in their BMI-SDS. In the latter study by D’Hondt et al., at baseline 50 overweight children (8 of which were obese) had a mean age of 11.6 ± 0.8 years and a baseline BMI z-score range of 1.55 ± 0.39 (1.00; 2.64). 2 years later, even these children’s BMI z-scores remained unchanged. These finding suggests that the significant reduction of BMI-SDS observed in our study likely depends on the lifestyle modifications reinforced by our team, rather than simply reflecting a physiological change in adiposity.
In conclusion, our study suggests that a non-intensive, long-term weight management program may significantly improve the degree of obesity and some cardiovascular risk factors in childhood. In addition, this non-intensive treatment (a small team approach) is more likely to be reimbursed by 3rd party payors making it more financially sustainable. Prospective studies with a larger population sample and comparison to a control group are warranted to confirm these findings.