A COM-B-guided life-style intervention reduces metabolic syndrome in obese and overweight adolescents: a multiphase examine in Vietnam

Study design

We carried out a three-phase sequential examine in a province of the Mekong Delta, southern Viet Nam, from October 2023 to May 2025.

Phase 1: a school-based cross-sectional survey to estimate the prevalence of MetS amongst adolescents with OW/OB.

Phase 2: a matched case–management examine to determine behavioral and medical danger components for MetS.

Phase 3: a 12-month school-based life-style intervention grounded within the COM-B mannequin.

Reporting adhered to the STROBE and TIDieR tips^17,18.

Participants

Inclusion standards: college students aged 11–14 years categorised as OW/OB in accordance with the WHO 2007 progress reference (physique mass index [BMI]-for-age > + 1 SD for obese; > +2 SD for weight problems)¹⁹; with out persistent endocrine, metabolic, or cardiovascular illnesses; and freed from acute sickness throughout recruitment. For Phase 3, individuals had been moreover required to satisfy the 2007 International Diabetes Federation (IDF) consensus definition of MetS for ages 10–16 years (central weight problems plus ≥ 2 extra standards)²⁰.

Exclusion standards: refusal to take part, anticipated change of residence, or medical contraindications to bodily exercise. Written knowledgeable consent was obtained from mother and father/guardians and assent from college students.

Sampling technique

Phase 1: Sample dimension for prevalence estimation was calculated utilizing a single-proportion method, assuming an OW/OB prevalence of 27.8%²¹, design impact of two, and a 6.1% margin of error. We used multistage cluster sampling stratified by city/rural areas, randomly chosen colleges, and carried out school-wide anthropometric screening.

Phase 2: Each MetS case was matched 1:1 with a non-MetS management by age, intercourse, college, and dietary standing.

Phase 3: A single-group pre–put up intervention required 300 individuals, based mostly on an anticipated enchancment price of 95%. We utilized stratified cluster sampling with peer pairing to help group-based conduct change and adopted individuals for 12 months (Supplementary Methods Appendix, pp: 1–2).

Schools had been notified one week prematurely (principal and homeroom academics). Students absent on the data-collection day had been contacted once more inside one week.

Data assortment and measurements

Data had been collected on college premises by a skilled analysis group. Anthropometry (weight, peak, waist and hip circumferences) adopted WHO procedures¹⁹. Blood strain (BP) was measured thrice at ≥ 1-minute intervals; the primary studying was discarded and the imply of the second and third readings was used. If the second and third readings differed by > 5 mmHg, a fourth measurement was taken and the imply of the third and fourth readings was recorded.

Fasting venous blood was collected to quantify plasma glucose, triglycerides (TG), high-density lipoprotein ldl cholesterol (HDL-C), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and glycated hemoglobin (HbA1c) utilizing internationally standardized strategies. Non-invasive evaluation of hepatic steatosis and fibrosis was carried out with FibroScan^® to acquire the managed attenuation parameter (CAP) and liver stiffness measurement (LSM)²².

Diagnostic thresholds and cut-offs adopted the IDF pediatric standards (fasting glucose ≥ 100 mg/dL [5.6 mmol/L]; systolic BP ≥ 130 mmHg and/or diastolic BP ≥ 85 mmHg; HDL-C < 40 mg/dL [1.03 mmol/L]; TG ≥ 150 mg/dL [1.7 mmol/L])²⁰; waist-to-hip ratio (WHR): elevated WHR > 0.89²³; waist-to-height ratio (WHtR): at-risk WHtR ≥ 0.46²⁴; American Diabetes Association (HbA1c)²⁵; and CAP ≥ 248 dB/m and LSM ≥ 5.5 kPa on FibroScan^®26,27.

Behavioral and life-style evaluation

A structured questionnaire captured dietary habits, bodily exercise, display screen time, and sleep. Students aged 11–12 years obtained help from academics or mother and father to make sure comprehension; older college students self-completed the questionnaire.

Intervention actions had been coordinated throughout colleges and households with collaboration amongst college employees, the analysis group, and fogeys.

• Health training was delivered month-to-month by means of interactive lessons, small-group discussions, and media movies. Content emphasised dangers of obesity-related persistent illnesses and the function of wholesome life. Parent workshops had been held quarterly to strengthen data and residential supervision.

• Dietary steering was offered through a vitamin handbook, pattern menus, and evidence-based guidelines (decreasing sugar, salt, and saturated fats, growing greens and fiber) to enhance food plan high quality whereas assembly developmental vitality wants. No absolute calorie-restriction (weight-loss) food plan was prescribed; the main focus was on meal high quality and consuming behaviors. Parents had been skilled to help dietary changes at residence.

• Physical exercise was inspired for ≥ 60 min/day on ≥ 5 days/week, together with college sports activities, strolling, biking, or home-based train. Students maintained exercise logs and took part in peer-pair competitions to reinforce motivation. Process information had been collected periodically to evaluate conduct change.

Intervention design (COM-B framework)

The 12-month intervention focused three elements^10,11:

Capability: well being training on vitamin and bodily exercise, with expertise coaching for meal planning and train scheduling.

Opportunity: enhancements to the college setting, provision of more healthy meals choices, and lively engagement of fogeys.

Motivation: aim setting, individualized suggestions, peer help, and recognition of progress.

Intervention reporting adopted the TIDieR guidelines¹⁸.

Adherence evaluation

Adherence was quantified on a six-point scale derived from WHO and CDC suggestions for pediatric weight problems administration^9,28, encompassing three domains (most 2 factors every):

Health training & household participation: attendance at ≥ 80% of classes with ≥ 1 member of the family collaborating in counseling.

Dietary conduct: sugar-sweetened drinks < 1 time/day and ≤ 3 instances/week; avoidance of consuming out > 3 instances/week or consuming whereas utilizing screens.

Physical exercise & sedentary conduct: ≥60 min/day of moderate-to-vigorous exercise on ≥ 5 days/week; leisure display screen time < 2 h/day on ≥ 5 days/week.

Scores had been recorded quarterly; the utmost cumulative rating was 24 over 12 months. Categories had been outlined as low (< 40%; imply rating < 2.5), average (40–<75%; imply 2.5–<4.5), and excessive (≥ 75%; imply ≥ 4.5). Scoring was based mostly on pupil self-reports, corroborated by academics/college well being employees and mother or father logs; discrepancies had been resolved by consensus.

The major end result was MetS remission at 12 months (now not assembly IDF standards). Secondary outcomes included modifications in anthropometric, biochemical, hepatic, and behavioral indicators (food plan, bodily exercise, display screen time, sleep). The adherence rating served each as an publicity (for subgroup analyses) and as a course of measure (Supplementary Methods Appendix, pp: 3–66).

Statistical evaluation

Descriptive statistics summarized baseline traits and pre–put up modifications. Paired t-tests or Wilcoxon signed-rank checks had been used for steady variables; McNemar’s take a look at for categorical variables. Logistic regression recognized baseline danger components for MetS. Generalized estimating equations (GEE) evaluated time × adherence interactions for steady outcomes. Receiver working attribute (ROC) evaluation assessed predictive fashions. Missing information had been dealt with by a number of imputation underneath a missing-at-random assumption²⁴. Analyses had been carried out in Stata, with two-sided p < 0.05 thought-about statistically vital (Supplementary Methods Appendix, pp: 67–76).

Ethics assertion

This examine was authorised by the Ethics Committee of the University of Medicine and Pharmacy at Ho Chi Minh City, Vietnam (Approval No. 505/HĐĐ-ĐHYD, dated May 4, 2023; ID: 23387-DHYD). All strategies had been carried out in accordance with related tips and laws. Written knowledgeable consent was obtained from all individuals and their authorized guardians previous to enrollment. All private information had been anonymized and saved strictly confidential.