V. P. Wickramasinghe

Assessment of body composition in Sri Lankan children: validation of a bioelectrical impedance prediction equation

Objective:To develop bioelectrical impedance analysis (BIA) equations to predict total body water (TBW) and fat-free mass (FFM) of Sri Lankan children.Subjects/Methods:Data were collected from 5- to 15-year-old healthy children. They were randomly assigned to validation (M/F: 105/83) and cross-validation (M/F: 53/41) groups. Height, weight and BIA were measured. TBW was assessed using isotope dilution method (D2O). Multiple regression analysis was used to develop preliminary equations and cross-validated on an independent group. Final prediction equation was constructed combining the two groups and validated by PRESS (prediction of sum of squares) statistics. Impedance index (height2/impedance; cm2/Ω), weight and sex code (male=1; female=0) were used as variables.Results:Independent variables of the final prediction equation for TBW were able to predict 86.3% of variance with root means-squared error (RMSE) of 2.1 l. PRESS statistics was 2.1 l with press residuals of 1.2 l. Independent variables were able to predict 86.9% of variance of FFM with RMSE of 2.7 kg. PRESS statistics was 2.8 kg with press residuals of 1.4 kg. Bland Altman technique showed that the majority of the residuals were within mean bias±1.96 s.d.Conclusions:Results of this study provide BIA equation for the prediction of TBW and FFM in Sri Lankan children. To the best of our knowledge there are no published BIA prediction equations validated on South Asian populations. Results of this study need to be affirmed by more studies on other closely related populations by using multi-component body composition assessment.

Distribution of obesity-related metabolic markers among 5-15 year old children from an urban area of Sri Lanka.

Background: Obesity-associated metabolic consequences are commonly seen among young South Asians. Objective: To assess the nutritional status, prevalence of metabolic derangements and to identify the validity of different obesity diagnostic criteria in the detection of metabolic derangements among 5–15 year old school children in the Colombo district of Sri Lanka. Materials and procedures: After a 12-hour overnight fast, blood was drawn for glucose, lipid profile and alanine amino transferase (ALT) enzyme. Oral glucose tolerance test (OGTT) was done with blood taken for random blood sugar 2 hours after glucose load. Height, weight, waist circumference (WC) and blood pressure were measured. Results: Nine hundred and twenty children were studied (boys, n = 547). Thirty-two (3.5%) were obese according to IOTF classification. Five (0.5%) and 57 (6.2%) children had systolic and diastolic hypertension. Twelve (1.3%) and three (0.3%) had impaired fasting glucose and 2-hour OGTT, respectively. One hundred and thirty-nine (15.1%) had hypercholesterolemia and 36 (3.9%) hypertriglyceridaemia. Two hundred and fifteen (23.3%) had low HDL. Fifteen (1.6%) had metabolic syndrome according to IDF definition. Two hundred and eighty-three (30.7%) had one metabolic derangement; 95 (10.3%) had two metabolic derangements; and 16 (1.7%) had three or more metabolic derangements. Sri Lankan BMI and WC obesity cut-offs had a higher sensitivity in detecting metabolic abnormalities than international cut-offs. Conclusion: Metabolic derangements are prevalent in children who were detected to be non-obese by anthropometric measures, and clinicians should actively look and correct them. New research is needed to study the long-term effects on health.

Defining anthropometric cut-off levels related to metabolic risk in a group of Sri Lankan children

Background: Body mass index (BMI) is widely used as a measure of adiposity. However, currently used cut-off values are not sensitive in diagnosing obesity in South Asian populations. Aim: To define BMI and waist circumference (WC), cut-off values representing percentage fat mass (%FM) associated with adverse health outcomes. Subjects and methods: A cross-sectional descriptive study of 285 5–14 year old Sri Lankan children (56% boys) was carried out. Fat mass (FM) was assessed using the isotope (D2O) dilution technique based on 2C body composition model. BMI and WC cut-off values were defined based on %FM associated with adverse health outcomes. Results: Sri Lankan children had a low fat free mass index (FFMI) and a high fat mass index (FMI). Individuals with the same BMI had %FM distributed over a wide range. Lean body tissue grew very little with advancing age and weight gain was mainly due to increases in body fat. BMI corresponding to 25% in males and 35% in females at 18 years was 19.2 kg/m2 and 19.7 kg/m2, respectively. WC cut-off values for males and females were 68.4 cm and 70.4 cm, respectively. Conclusion: This chart analysis clearly confirms that Sri Lankan children have a high %FM from a young age. With age, more changes occur in FM than in fat free mass (FFM). Although the newly defined BMI and WC cut-off values appear to be quite low, they are comparable to some recent data obtained in similar populations.

Use of Skin-Fold Thickness in Sri Lankan Children: Comparison of Several Prediction Equations

ObjectiveThere are many prediction equations available in the literature for the assessment of body composition from skinfold thickness (SFT). This study aims to cross validate some of those prediction equations to determine the suitability of their use on Sri Lankan children.MethodsHeight, weight and SFT of 5 different sites were measured. Total body water was assessed using the isotope dilution method (D2O). Percentage Fat mass (%FM) was estimated from SFT using prediction equations described by five authors in the literature.ResultsFive to 15 year old healthy, 282 Sri Lankan children were studied. The equation of Brook gave Ihe lowest bias but limits of agreement were high. Equations described by Deurenberg et al gave slightly higher bias but limits of agreement were narrowest and bias was not influence by extremes of body fat. Although prediction equations did not estimate %FM adequately, the association between %FM and SFT measures, were quite satisfactory.ConclusionWe conclude that SFT can be used effectively in the assessment of body composition in children. However, for the assessment of body composition using SFT, either prediction equations should be derived to suit the local populations or existing equations should be cross-validated to determine the suitability before its application.

Development of Height-weight Based Equation for Assessment of Body Composition in Sri Lankan Children

ObjectiveTo develop a height and weight based equation to estimate total body water (TBW) in Sri Lankan children.MethodsCross sectional descriptive study done involving 5–15 year old healthy children. Height and weight were measured. TBW was assessed using isotope dilution method (D2O) and fat free mass (FFM) calculated. Multiple regression analysis was used to develop prediction equation and validated using PRESS statistical technique. Height, weight and sex code (male=1; female=0) were used as prediction variables.ResultsThis study provides height and weight equation for the prediction of TBW in Sri Lankan children. To the best of our knowledge there are no published height weight prediction equations validated on South Asian populations.ConclusionResults of this study need to be affirmed by more studies on other closely related populations by using multicomponent body composition.

Validity of newly-developed BMI and waist cut-off values for Sri Lankan children

Background: Excess body fat leads to obesity-related morbidity and population/ethnicity-specific cut-off values of anthropometric measures are useful for better diagnosis. This study assesses the suitability of newly-developed Sri Lankan anthropometric cut-off values in the diagnosis of obesity in Sri Lankan children. Methods: A cross-sectional study was conducted at University of Colombo, Sri Lanka involving 5–15 year old children. Height, weight, waist (WC), and hip (HC) circumferences were measured. Total body fat (FM) was measured using whole body BIA. WHR and WHtR were calculated. Validity of anthropometric measures in detecting childhood obesity (Sri Lankan BMI/WC; IOTF, WHO, British and CDC BMI and British WC cut-off values) were evaluated. Results: Nine hundred and twenty children were assessed. FM showed significant associations with BMI (r = 0.92, p < 0.001), WC (r = 0.90, p < 0.001) and HC (r = 0.85, p < 0.001), but poor association with WHR (r = 0.17, p < 0.001). However, WHtR had a high association with FM (r = 0.75, p < 0.001) and %FM (r = 0.78, p < 0.001). Based on %FM cut-offs, 85 (22.8%) girls and 101 (18.5%) boys were obese. All international anthropometric cut-off values under-estimated obesity. Sri Lankan WC and BMI cut-off values over-estimated obesity. International BMI based cut-off values had high specificity (>99%) but a low sensitivity (∼12–33%), while Sri Lankan BMI cut-off values had high sensitivity (>93.1) but low specificity (>79.7). Conclusions: Internationally available BMI cut-off values are poor in diagnosing obesity in Sri Lankan children. Newly developed Sri Lankan BMI cut-off values for children improved the diagnosis. WC can be used successfully as an alternative diagnostic tool of obesity.

Hereditary hemorrhagic telangiectasia, liver disease and elevated serum testosterone (Osler–Weber–Rendu syndrome): a case report

AbstractBackground A Sri Lankan girl with hereditary hemorrhagic telangiectasia (Osler–Weber–Rendu syndrome) is described.Case presentationShe presented with recurrent spontaneous epistaxis, pulmonary arterio venous malformation and oral telangiectasia. A diagnosis of Hereditary hemorrhagic telangiectasia (Osler–Weber–Rendu syndrome) was made based on the presence of three Curacao criteria (out of four). Evaluations of her jaundice revealed chronic parenchymal liver disease with multiple nodules in the liver with early portal hypertension. She had a muscular build, with elevated serum testosterone but low serum dehydroepiandrosterone sulphate levels. This could be attributed to impaired sulfation of dehydroepiandrosterone due to portocaval shunting of blood, leading to hyperandrogenemia.ConclusionsHyperandorogenemia due impaired sulfation of dehydroepiandrosterone as a result of portocaval shunting is seen in Hereditary haemorrhagic telangiectasia.

Validity of BMI as a measure of obesity in Australian caucasian and Australian Sri Lankan children

BACKGROUND Body mass index (BMI) is used to diagnose obesity. However, its ability to predict the percentage fat mass (%FM) reliably is doubtful. Therefore validity of BMI as a diagnostic tool of obesity is questioned. AIM This study is focused on determining the ability of BMI-based cut-off values in diagnosing obesity among Australian children of white Caucasian and Sri Lankan origin. SUBJECTS AND METHODS Height and weight was measured and BMI (W/H2) calculated. Total body water was determined by deuterium dilution technique and fat free mass and hence fat mass derived using age- and gender-specific constants. A %FM of 30% for girls and 20% for boys was considered as the criterion cut-off level for obesity. BMI-based obesity cut-offs described by the International Obesity Task Force (IOTF), CDC/NCHS centile charts and BMI-Z were validated against the criterion method. RESULTS There were 96 white Caucasian and 42 Sri Lankan children. Of the white Caucasians, 19 (36%) girls and 29 (66%) boys, and of the Sri Lankans 7 (46%) girls and 16 (63%) boys, were obese based on %FM. The FM and BMI were closely associated in both Caucasians (r=0.81, P<0.001) and Sri Lankans (r=0.92, P<0.001). Percentage FM and BMI also had a lower but significant association. Obesity cut-off values recommended by IOTF failed to detect a single case of obesity in either group. However, NCHS and BMI-Z cut-offs detected cases of obesity with low sensitivity. CONCLUSIONS BMI is a poor indicator of percentage fat and the commonly used cut-off values were not sensitive enough to detect cases of childhood obesity in this study. In order to improve the diagnosis of obesity, either BMI cut-off values should be revised to increase the sensitivity or the possibility of using other indirect methods of estimating the %FM should be explored.