Culturally tailored and comprehensive prevention strategies are vital for addressing the epidemic of obesity and rising rates of type 2 diabetes, particularly among ethnic and racial minority youth (1). The Diabetes Prevention Program (DPP) has demonstrated the efficacy of lifestyle modification in adults (2). However, studies on lifestyle programs for diabetes prevention in youth are limited, and none have reported comprehensive physical fitness outcomes (3–5). We conducted a pilot prospective uncontrolled study (ClinicalTrials.gov identifier NCT03042936) evaluating feasibility and changes in metabolic and physical fitness parameters for the Insulin Superheroes Club (ISC) curriculum, a DPP designed for youth from culturally diverse, minority backgrounds.

Youth aged 7–15 years and a parent with impaired glucose tolerance enrolled in the ISC as a supplement to the Centers for Disease Control and Prevention’s adult DPP. The ISC is a 12-month, multilevel program that includes 16 weekly (phase 1), 3 biweekly (phase 2), and 6 monthly (phase 3) sessions. Participants attended sessions that included 60 min of physical fitness and 30 min of education. The education portion included interactive teaching of health-related topics (e.g., nutrition, exercise, physiology, mindfulness, and stress reduction) using hands-on learning activities (e.g., cooking, crafts, games, and role-play). All physical fitness activities incorporated moderate-intensity exercises (e.g., push-ups, yoga, basketball, tag, and dance).

Measurements at baseline and 16 weeks included height, weight, waist circumference, manual blood pressure, body composition (InBody 570 multifrequency bioimpedance analyzer), hemoglobin A1c (HbA1c) (A1CNow+), nonfasting lipid profile (Cholestech LDX), and physical fitness (6-min walk test, handgrip strength, sit-and-reach, and shuttle run). Wilcoxon signed rank test (adjusting for household clusters) and generalized estimating equations compared measures at baseline and 16 weeks. P < 0.002 was considered significant after Bonferroni multiple comparison correction (0.05 ÷ 23 = 0.0022).

Participants were 33 youth (from 16 households), aged 10.8 ± 2.0 years, 58% female, 88% Hispanic, 24% with overweight, 39% with obesity, 76% receiving government food assistance, and 100% with lower socioeconomic status (Hollingshead score of 4 in 6% and 5 in 94%). Five subjects (15%) were lost to follow-up. The baseline HbA1c of subjects who dropped out were not significantly different from that of completers (P = 0.13, Mann-Whitney U test). All subjects were included in intention-to-treat analysis. The single imputation method, baseline observation carried forward (BOCF), was used for subjects missing values at 16 weeks.

From baseline to 16 weeks, HbA1c significantly improved, while BMI z score, percent body fat, diastolic blood pressure, 6-min walk distance, right handgrip strength, and lower-body flexibility nominally improved (Table 1). The percentage of subjects with HbA1c ≥5.7% (39 mmol/mol) decreased from 61 to 15% (P < 0.0001) when using BOCF or 8% when analyzing only subjects with HbA1c measurement at 16 weeks.

Table 1

Metabolic health parameters and physical fitness

VariablesBaselinePost 16 weeksPaired differencesP value
Metabolic parameters     
 BMI (kg/m2) 21.5 (19.1, 26.5) 21.6 (19.0, 26.5) −0.1 (−0.5, 0.1) 0.08 
 BMI z score 1.23 (0.79, 2.00) 1.13 (0.46, 2.00) −0.05 (−0.18, 0) 0.003* 
 Percent body fat (%) 32.8 (28.0, 40.0) 31.6 (23.6, 39.8) −1.5 (−3.6, 0) 0.008* 
 Waist circumference (cm) 74.0 (66.5, 83.5) 76.0 (64.1, 83.5) 0 (−2.5, 2.1) 0.91 
 Waist circumference z score 0.13 (−0.13, 0.63) 0.03 (−0.40, 0.69) 0 (−0.26, 0.11) 0.23 
 Sagittal abdominal (cm) 17.0 (16.0, 19.8) 17.8 (15.3, 19.5) 0 (−1.0, 0.85) 0.21 
 HbA1c (%) 5.8 (5.6, 5.9) 5.3 (5.1, 5.5) −0.5 (−0.6, −0.2) 0.0017** 
 HbA1c (mmol/mol) 40 (38, 41) 34 (32, 37) −5.5 (−6.6, −2.2) 0.0017** 
 Triglycerides (mmol/L)# 0.98 (0.81, 1.56) 1.10 (0.73, 1.60) 0 (−0.07, 0.49) 0.41 
 Total cholesterol (mmol/L)# 3.78 (3.47, 4.03) 3.80 (3.47, 4.16) 0 (−0.10, 0.28) 0.65 
 LDL cholesterol (mmol/L)# 1.86 (1.66, 2.33) 2.02 (1.66, 2.33) 0 (−0.16, 0.28) 0.57 
 HDL cholesterol (mmol/L)# 1.22 (0.96, 1.45) 1.16 (0.98, 1.40) 0 (−0.13, 0) 0.06 
 Non-HDL cholesterol (mmol/L)# 2.43 (2.17, 2.92) 2.56 (2.28, 3.13) 0 (−0.05, 0.26) 0.17 
 SBP (mmHg) 106 (100, 112) 102 (98, 108) 0 (−8, 0) 0.16 
 SBP z score 0.25 (−0.27, 0.95) −0.06 (−0.50, 0.18) −0.07 (−0.82, 0) 0.13 
 DBP (mmHg) 68 (60, 70) 64 (58, 70) −2 (−8, 0) 0.01* 
 DBP z score 0.53 (0, 0.88) 0.14 (−0.40, 0.54) −0.24 (−0.73, 0) 0.01* 
Physical fitness     
 6-Min walk (m) 647.88 (568.45, 731.95) 685.80 (614.17, 797.33) 30.66 (0, 216.81) 0.01* 
 Right handgrip (kg) 18.0 (14.0, 26.0) 19.0 (16.0, 26.0) 1.0 (0, 2.0) 0.01* 
 Left handgrip (kg) 18.0 (14.0, 23.5) 18.0 (15.0, 21.0) 0 (0, 1.0) 0.93 
 Handgrip combined (kg) 36.0 (28.0, 46.5) 36.0 (30.0, 46.0) 1.5 (0, 3.0) 0.07 
 Shuttle run (s) 9.083 (9.008, 11.003) 9.057 (8.064, 10.065) 0 (−0.960, 0.035) 0.21 
 Sit-and-reach (cm) 19.0 (11.5, 27.0) 27.0 (20.0, 31.0) 3.7 (0, 10.8) 0.006* 
VariablesBaselinePost 16 weeksPaired differencesP value
Metabolic parameters     
 BMI (kg/m2) 21.5 (19.1, 26.5) 21.6 (19.0, 26.5) −0.1 (−0.5, 0.1) 0.08 
 BMI z score 1.23 (0.79, 2.00) 1.13 (0.46, 2.00) −0.05 (−0.18, 0) 0.003* 
 Percent body fat (%) 32.8 (28.0, 40.0) 31.6 (23.6, 39.8) −1.5 (−3.6, 0) 0.008* 
 Waist circumference (cm) 74.0 (66.5, 83.5) 76.0 (64.1, 83.5) 0 (−2.5, 2.1) 0.91 
 Waist circumference z score 0.13 (−0.13, 0.63) 0.03 (−0.40, 0.69) 0 (−0.26, 0.11) 0.23 
 Sagittal abdominal (cm) 17.0 (16.0, 19.8) 17.8 (15.3, 19.5) 0 (−1.0, 0.85) 0.21 
 HbA1c (%) 5.8 (5.6, 5.9) 5.3 (5.1, 5.5) −0.5 (−0.6, −0.2) 0.0017** 
 HbA1c (mmol/mol) 40 (38, 41) 34 (32, 37) −5.5 (−6.6, −2.2) 0.0017** 
 Triglycerides (mmol/L)# 0.98 (0.81, 1.56) 1.10 (0.73, 1.60) 0 (−0.07, 0.49) 0.41 
 Total cholesterol (mmol/L)# 3.78 (3.47, 4.03) 3.80 (3.47, 4.16) 0 (−0.10, 0.28) 0.65 
 LDL cholesterol (mmol/L)# 1.86 (1.66, 2.33) 2.02 (1.66, 2.33) 0 (−0.16, 0.28) 0.57 
 HDL cholesterol (mmol/L)# 1.22 (0.96, 1.45) 1.16 (0.98, 1.40) 0 (−0.13, 0) 0.06 
 Non-HDL cholesterol (mmol/L)# 2.43 (2.17, 2.92) 2.56 (2.28, 3.13) 0 (−0.05, 0.26) 0.17 
 SBP (mmHg) 106 (100, 112) 102 (98, 108) 0 (−8, 0) 0.16 
 SBP z score 0.25 (−0.27, 0.95) −0.06 (−0.50, 0.18) −0.07 (−0.82, 0) 0.13 
 DBP (mmHg) 68 (60, 70) 64 (58, 70) −2 (−8, 0) 0.01* 
 DBP z score 0.53 (0, 0.88) 0.14 (−0.40, 0.54) −0.24 (−0.73, 0) 0.01* 
Physical fitness     
 6-Min walk (m) 647.88 (568.45, 731.95) 685.80 (614.17, 797.33) 30.66 (0, 216.81) 0.01* 
 Right handgrip (kg) 18.0 (14.0, 26.0) 19.0 (16.0, 26.0) 1.0 (0, 2.0) 0.01* 
 Left handgrip (kg) 18.0 (14.0, 23.5) 18.0 (15.0, 21.0) 0 (0, 1.0) 0.93 
 Handgrip combined (kg) 36.0 (28.0, 46.5) 36.0 (30.0, 46.0) 1.5 (0, 3.0) 0.07 
 Shuttle run (s) 9.083 (9.008, 11.003) 9.057 (8.064, 10.065) 0 (−0.960, 0.035) 0.21 
 Sit-and-reach (cm) 19.0 (11.5, 27.0) 27.0 (20.0, 31.0) 3.7 (0, 10.8) 0.006* 

Median (interquartile range), at baseline and 16 weeks, and paired sample differences shown. DBP, diastolic blood pressure; SBP, systolic blood pressure.

*

P < 0.05 (nominally significant);

**

P < 0.002 (significant after correction for multiple comparisons).

#

Nonfasting lipid panel.

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After 16 weeks of the phase 1 component of the ISC, participants displayed significantly improved metabolic and physical fitness parameters. These beneficial outcomes suggest that a family-based program that involves lifestyle education, behavior modification, and goal-driven exercise can be effective in a predominantly Latino, socioeconomically disadvantaged population. The durability of these positive outcomes will be determined at 12-month follow-up of this cohort.

Acknowledgments. The authors are grateful to Connie S. Binkowitz (Program Director, Health Innovations, YMCA of Memphis & the Mid-South), Mariam C. Ebeid (Research Assistant, University of Tennessee Health Science Center), and Kiran Ashok (Research Assistant, University of Tennessee Health Science Center) for program support and thank the YMCA of Memphis & the Mid-South, the Fogelman Downtown YMCA in Memphis, TN, and all the families who participated in this study.

Funding. This study was funded by the Memphis Research Consortium and the Le Bonheur Children’s Foundation Research Institute.

Duality of Interest. J.C.H. is the recipient of an unrestricted research grant from Rhythm Pharmaceuticals. No other potential conflicts of interest relevant to this article were reported.

Author Contributions. C.M. contributed to the design and implementation of the study and wrote the manuscript. T.J. contributed to statistical analysis and manuscript editing. K.M.D. contributed to statistical analysis and manuscript editing. A.M.J., S.Y.S., and M.R.M. contributed to the implementation of the study and data acquisition. M.E.H. contributed to data interpretation and manuscript editing. J.C.H. contributed to statistical analysis and interpretation of data and wrote the manuscript. All authors approved the final version. All authors had full access to the study data and were responsible for the final decision to submit the manuscript. C.M. and J.C.H. are the guarantors of this work and, as such, had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Prior Presentation. Parts of this study were presented in abstract form at the 63rd Annual Meeting of the American College of Sports Medicine, 7th World Congress on Exercise is Medicine, and World Congress on The Basic Science of Energy Balance, Boston, MA, 1–4 June 2016, as well as at the 34th Annual Scientific Meeting of The Obesity Society, New Orleans, LA, 31 October to 4 November 2016.

Clinical trial reg. no. NCT03042936, clinicaltrials.gov.

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