Waist circumference percentiles for Singaporean children and adolescents aged 6-17 years

Waist circumference and waist-to-height ratio in 7-year-old children-WHO Childhood Obesity Surveillance Initiative

Childhood obesity is a serious global health problem. Waist circumference (WC) and waist-to-height ratio (WHtR) reflect body fat distribution in children. The objectives of this study were to assess WC and WHtR in 7-year-old children and to determine body mass index (BMI), WC, and WHtR differences in children from 10 selected countries across Europe (Bulgaria, Czechia, Greece, Ireland, Latvia, Lithuania, North Macedonia, Norway, Spain, and Sweden) participating in the World Health Organization (WHO) Europe Childhood Obesity Surveillance Initiative (COSI). The 50th and 90th percentile of WC (according to COSI and "Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS" (IDEFICS) cutoff values) and WHtR above 0.5 were used as measures of abdominal obesity in a unique sample of 38,975 children aged 7.00-7.99 years. Southern European countries, including Greece and Spain, showed significantly higher BMI, WC, and WHtRin both genders (p < 0.0001) than Eastern and Northern Europe. The highest values for WC were observed in Greece (60.8 ± 7.36 cm boys; 60.3 ± 7.48 cm girls), North Macedonia (60.4 ± 7.91 cm boys; 59.0 ± 8.01 cm girls), and Spain (59.7 ± 6.96 cm boys; 58.9 ± 6.77 cm girls). WC and WHtRin may add an information about the occurrence of central obesity in children.

Reference Curves of Selected Circumferential Parameters for Czech Children Aged 6 to 11 Years

(1) Background/objective: the globally discussed current issue is the increasing body weight of the population. This trend is observed in all age categories. Pediatricians and anthropologists use BMI percentile curves to determine the optimal body weight of children, based on which the child is categorized in the category of underweight, normal weight, overweight, or obese. Medical or anthropological examinations also use some methods to determine the amount of body fat. In addition to evaluating amounts of body fat, it is important to assess its distribution. The distribution of fat in the body, especially in terms of disproportionate distribution, is a risk factor for health complications, especially in terms of metabolic and health risk. Part of monitoring children’s growth is also measuring and evaluating circumferential parameters, such as abdominal circumference, gluteal circumference, and waist circumference. This study aimed to define age- and gender-specific reference curves for waist circumference (WC), abdominal circumference (AbC), and gluteal circumference (GC) in Czech children. (2) Methods: data on children’s circumferential parameters were collected via anthropometric measurements. The research sample consisted of 2093 children aged 6–11 years (boys, n = 1008; girls, n = 1085). Only children with parental informed consent were included. The statistical analysis was performed separately by age and gender using SPSS v. 22. Anthropometric data were summarized by mean and standard deviation. The percentile curves of WC, AbC, and GC were calculated (P3, P10, P25, P50, P75, P90, P97) in R 3.4.2 software (R Foundation for Statistical Computing, Vienna, Austria) using the gamlss package. (3) Results and conclusions: the study developed age- and gender-specific percentile curves of WC, AbC, and GC for Czech children aged 6–11 years. All parameters increased with age in both boys and girls. Generally, the boys had higher WC and AbC than did girls, but girls had higher GC than did boys. Female and male median WC percentiles (M) increased from the age of 6. Both girls’ and boys’ median percentiles showed a continuous increase. We found similar trends in the median GC and AbC percentile curves. All percentile curves showed similar trends in both sexes, but the 90th and 97th WC percentiles in boys were exceptions: from the age of 10, they exceeded the values of girls, reaching their peak at the age of 11 followed by a decrease in the case of the 97th percentile and a plateau in the case of the 90th percentile. This study serves as a reference to enrich the methods of evaluation of somatic and medical status in Czech children. Up–to–date percentile curves would be a practical addition to the BMI percentiles for the screening and evaluation of overweight and obese conditions and the related risks of abdominal obesity in the pediatric population.

Use of a Mobile Lifestyle Intervention App as an Early Intervention for Adolescents With Obesity: Single-Cohort Study

Background

Effective, resource-efficient treatment is urgently needed to address the high rates of pediatric and adolescent obesity. This need has been accelerated by the COVID-19 pandemic. The use of a mobile health tool as an early intervention before a clinic-based multidisciplinary weight management program could be an effective treatment strategy that is appropriate during a pandemic.

Objective

This study aims to assess the effectiveness of and adolescent engagement with a mobile app–based lifestyle intervention program as an early intervention before enrollment in a clinic-based multidisciplinary weight management program.

Methods

This prospective single-cohort study involved adolescents, aged 10-16 years, who were overweight and obese (defined as BMI percentile above the 85th percentile). Participants used the mobile Kurbo app as an early intervention before enrolling in a clinic-based multidisciplinary weight management program. Kurbo’s health coaches provided weekly individual coaching informed by a model of supportive accountability via video chat, and participants self-monitored their health behavior. The implementation of Kurbo as an early intervention was evaluated using the reach, effectiveness, adoption, implementation, and maintenance framework by reach (number who consented to participate out of all patients approached), implementation (Kurbo engagement and evaluation), and effectiveness as measured by the primary outcome of the BMI z-score at 3 months. Secondary outcome measures included changes in body fat percentage, nutrition and physical activity levels, and quality of life at 3 months. Maintenance was defined as the outcome measures at 6-month follow-up.

Results

Of the 73 adolescents who were approached for enrollment, 40 (55%) of adolescents were recruited. The mean age was 13.8 (SD 1.7) years, and the mean BMI z-score was 2.07 (SD 0.30). In the multiethnic Asian sample, 83% (33/40) of the participants had household incomes below the national median. Kurbo engagement was high, with 83% (33/40) of participants completing at least 7 coaching sessions. In total, 78% (18/23) of participants rated the app as good to excellent and 70% (16/23) stated that they would recommend it to others. There were no statistically significant changes in BMI z-scores at 3 months (P=.19) or 6 months (P=.27). Participants showed statistically significant improvements in measured body fat percentage, self-reported quality of life, and self-reported caloric intake from the 3-day food diaries at 3 and 6 months.

Conclusions

The use of Kurbo before enrollment in an outpatient multidisciplinary clinical care intervention is a feasible strategy to expand the reach of adolescent obesity management services to a low-income and racially diverse population. Although there was no significant change in BMI z-scores, the use of Kurbo as an early intervention could help to improve quality of life and reduce body fat percentage and total caloric intake.

Developing waist circumference, waist-to-height ratio percentile curves for Pakistani children and adolescents aged 2-18 years using Lambda-Mu-Sigma (LMS) method

Objectives Children from different countries and with different ethnic backgrounds have a distinct pattern of central fat deposition. Therefore, it is essential to develop population-specific percentiles of waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-height ratio exponent (WHtR (exp)) for the evaluation of central obesity. The objective of this study was to develop age-and-gender-specific smoothed WC and WHtR percentile curves for the Pakistani children and adolescents aged 2-18 years. Methods A cross-sectional data-set from a multi-ethnic anthropometric survey was considered. A sample of 10,668 healthy subjects (boys = 51.92%; and girls = 48.08%), aged 2-18 years was studied. Height (cm) and WC (cm) of each subject was measured under standard procedure and WHtR & WHtR (exp) were calculated. Age-and-gender-specific smoothed curves were obtained using the lambda-mu-sigma (LMS) method and compared with percentile curves obtained from different countries. Results Except few early ages, the WC values increased with age in both sexes. Both boys and girls had approximately similar WC during 6-11 years of age and after age of 11, the boys had larger WC than the girls had. For WHtR, the centile curves showed a continuous decrease by 16 years of age and then increased gradually. WHtR of the girls in various ages were having similar or higher than those of the boys. In comparison of WC 50th and 90th percentiles with other countries, it was found that except few ages, the Pakistani children had larger WC than the other reference populations and the results of WHtR were also comparable to the other nations. Conclusions We present new reference data of WC, WHtR and WHtR (exp) using a representative sample of the Pakistani children aged 2-18 years. These reference values can be used provisionally for early detection of central obesity and its associated risks in the Pakistani children.

International Waist Circumference Percentile Cutoffs for Central Obesity in Children and Adolescents Aged 6 to 18 Years

CONTEXT

No universal waist circumference (WC) percentile cutoffs used have been proposed for screening central obesity in children and adolescents.

OBJECTIVE

To develop international WC percentile cutoffs for children and adolescents with normal weight based on data from 8 countries in different global regions and to examine the relation with cardiovascular risk.

DESIGN AND SETTING

We used pooled data on WC in 113,453 children and adolescents (males 50.2%) aged 4 to 20 years from 8 countries in different regions (Bulgaria, China, Iran, Korea, Malaysia, Poland, Seychelles, and Switzerland). We calculated WC percentile cutoffs in samples including or excluding children with obesity, overweight, or underweight. WC percentiles were generated using the general additive model for location, scale, and shape (GAMLSS). We also estimated the predictive power of the WC 90th percentile cutoffs to predict cardiovascular risk using receiver operator characteristics curve analysis based on data from 3 countries that had available data (China, Iran, and Korea). We also examined which WC percentiles linked with WC cutoffs for central obesity in adults (at age of 18 years).

MAIN OUTCOME MEASURE

WC measured based on recommendation by the World Health Organization.

RESULTS

We validated the performance of the age- and sex-specific 90th percentile WC cutoffs calculated in children and adolescents (6-18 years of age) with normal weight (excluding youth with obesity, overweight, or underweight) by linking the percentile with cardiovascular risk (area under the curve [AUC]: 0.69 for boys; 0.63 for girls). In addition, WC percentile among normal weight children linked relatively well with established WC cutoffs for central obesity in adults (eg, AUC in US adolescents: 0.71 for boys; 0.68 for girls).

CONCLUSION

The international WC cutoffs developed in this study could be useful to screen central obesity in children and adolescents aged 6 to 18 years and allow direct comparison of WC distributions between populations and over time.