A five year longitudinal study investigating the prevalence of childhood obesity: comparison of BMI and waist circumference.

OBJECTIVE: The purpose of this study was to examine the prevalence of obesity over time in the same individuals comparing body mass index (BMI), waist circumference (WC) and waist to height ratio (WHtR). STUDY DESIGN: Five year longitudinal repeated measures study (2005-2010). Children were aged 11-12 (Y7) years at baseline and measurements were repeated at age 13-14 (Y9) years and 15-16 (Y11) years. METHODS: WC and BMI measurements were carried out by the same person over the five years and raw values were expressed as standard deviation scores (sBMI and sWC) against the growth reference used for British children. RESULTS: Mean sWC measurements were higher than mean sBMI measurements for both sexes and at all assessment occasions and sWC measurements were consistently high in girls compared to boys. Y7 sWC = 0.792 [95% confidence interval (CI) 0.675-0.908], Y9 sWC = 0.818 (95%CI 0.709-0.928), Y11 sWC = 0.943 (95%CI 0.827-1.06) for boys; Y7 sWC = 0.843 (0.697-0.989), Y9 sWC = 1.52 (95%CI 1.38-0.67), Y11 sWC = 1.89 (95%CI 1.79-2.04) for girls. Y7 sBMI = 0.445 (95%CI 0.315-0.575), Y9 sBMI = 0.314 (95%CI 0.189-0.438), Y11 sBMI = 0.196 (95%CI 0.054-0.337) for boys; Y7 sBMI = 0.353 (0.227-0.479), Y9 sBMI = 0.343 (95%CI 0.208-0.478), Y11 sBMI = 0.256 (95%CI 0.102-0.409) for girls. The estimated prevalence of obesity defined by BMI decreased in boys (18%, 12% and 10% in Y 7, 9 and 11 respectively) and girls (14%, 15% and 11% in Y 7, 9 and 11). In contrast, the prevalence estimated by WC increased sharply (boys; 13%, 19% and 23%; girls, 20%, 46% and 60%). CONCLUSION: Central adiposity, measured by WC is increasing alongside a stabilization in BMI. Children appear to be getting fatter and the additional adiposity is being stored centrally which is not detected by BMI. These substantial increases in WC are a serious concern, especially in girls.

Area-level deprivation and adiposity in children: is the relationship linear?

OBJECTIVE: It has been suggested that childhood obesity is inversely associated with deprivation, such that the prevalence is higher in more deprived groups. However, comparatively few studies actually use an area-level measure of deprivation, limiting the scope to assess trends in the association with obesity for this indicator. Furthermore, most assume a linear relationship. Therefore, the aim of this study was to investigate associations between area-level deprivation and three measures of adiposity in children: body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). DESIGN: This is a cross-sectional study in which data were collected on three occasions a year apart (2005-2007). SUBJECTS: Data were available for 13,333 children, typically aged 11-12 years, from 37 schools and 542 lower super-output areas (LSOAs). MEASURES: Stature, mass and WC. Obesity was defined as a BMI and WC exceeding the 95th centile according to British reference data. WHtR exceeding 0.5 defined obesity. The Index of Multiple Deprivation affecting children (IDACI) was used to determine area-level deprivation. RESULTS: Considerable differences in the prevalence of obesity exist between the three different measures. However, for all measures of adiposity the highest probability of being classified as obese is in the middle of the IDACI range. This relationship is more marked in girls, such that the probability of being obese for girls living in areas at the two extremes of deprivation is around half that at the peak, occurring in the middle. CONCLUSION: These data confirm the high prevalence of obesity in children and suggest that the relationship between obesity and residential area-level deprivation is not linear. This is contrary to the 'deprivation theory' and questions the current understanding and interpretation of the relationship between obesity and deprivation in children. These results could help make informed decisions at the local level.

Nutritional profile of continuous ambulatory peritoneal dialysis patients.

Undernutrition in dialysis patients contributes to their morbidity and mortality. This is a cross-sectional study of the nutritional status of 61 patients treated with continuous ambulatory peritoneal dialysis (CAPD). They were studied with emphasis on assessment of their nutritional intake, anthropometric measurements, and evaluation of biochemical parameters. The correlation between the rate of CAPD peritonitis and these measurements was also examined. The majority of the patients (63.1%) had inadequate protein intake ( < or = 1.2 g/kg/day). A comparable percentage had a low energy intake ( < or = 30 kcal/kg/day). Moderate malnutrition, as assessed by a low triceps skinfold thickness (TST) or a reduced midarm muscle circumference (MAMC) of < or = 20th percentile, was detected in 52% and 39% of the patients, respectively. Severe malnutrition (TST or MAMC < or = 10th percentile) was present in 36% of the patients. The serum insulin-like growth factor I (IGF-I) proved to be the most useful biochemical marker of malnutrition. It showed a positive correlation with TST (r = 0.325; p < 0.05). No significant correlation was observed with other short-life proteins such a transferrin or prealbumin. However, stepwise regression analysis showed the predictive value of serum IGF-I for anthropometric values to be low (adjusted R2 = 34.6%). Wasted patients did not appear to have more infections when compared to their healthier counterparts. However, a weak correlation was observed between TST and the number of peritonitis episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Time of onset of chest pain in acute myocardial infarction.

We studied the time of onset of chest pain in 1099 patients admitted to a coronary care unit with myocardial infarction using a statistical model. Statistical analysis demonstrated an excess of infarcts with time of onset of chest pain at 0700 hours (14%) and at midnight (11%), with the remaining infarct population (75%) forming a background distribution over the 24 hr.