Excess weight and sleep-disordered breathing.

Excess weight is a well-established predictor of sleep-disordered breathing (SDB). Clinical observations and population studies throughout the United States, Europe, Asia, and Australia have consistently shown a graded increase in the prevalence of SDB as body mass index, neck girth, or other measures of body habitus increases. Clinical studies of weight loss and longitudinal population studies provide strong support for a causal association. The role of excess body weight, a modifiable risk factor, with SDB raises many questions relevant to clinical practice and public health. The topic takes on added importance with the alarming rate of weight gain in children as well as adults in industrialized nations. Among adults ages 30-69 yr, averaging over the estimated United States 2003 age, sex, and BMI distributions, we estimate that approximately 17% of adults have mild or worse SDB (apnea-hypopnea index > or = 5) and that 41% of those adults have SDB "attributable" to having a body mass index of > or =25 kg/m(2). Similarly, we estimate that approximately 5.7% of adults have moderate or worse SDB (apnea-hypopnea index > or = 15) and that 58% of those adults have SDB attributable to excess weight. Clearly, if the expanding epidemic of obesity seen in the United States continues, the prevalence of SDB will almost certainly increase, along with the proportion of SDB attributable to obesity.     

Predictors of ratio of placental weight to fetal weight in multiethnic community.

OBJECTIVE--To determine whether placental ratio is influenced by maternal ethnic origin, obesity, hypertension, and haematological indices of iron deficiency anaemia. DESIGN--Observational study. SETTING--District general hospital in Birmingham. SUBJECTS--692 healthy nulliparous pregnant women, of whom 367 were European, 213 Asian, 99 Afro-Caribbean, and 13 of other or undocumented ethnic origin. MAIN OUTCOME MEASURES--Placental ratio and maternal body mass index, blood pressure, and haematological indices. RESULTS--Though birth weight and placental weight were lower in Asian women than in other groups, mean placental ratio was similar in Asian (19.5% (SD 3.3%)), European (20.0% (4.0%)), and Afro-Caribbean women (20.4% (5.3%)). Gestational age at birth was the main predictor of placental ratio in the univariate analysis (r = -0.34, P < 0.001) and multivariate analysis. The only other significant predictor of placental ratio in multivariate analysis was maternal body mass index, which was positively associated with placental ratio (r = 0.1, P = 0.01). Mean (SD) placental ratio was not significantly higher in women who developed gestational hypertension (20.4% (4.5%)) and pre-eclampsia (23.3% (7.3%)) than in normal women (19.8% (3.8%)). No evidence of a relation between placental ratio and first antenatal visit haemoglobin concentration or mean cell volume was detected, and placental ratio was not associated with change in mean cell volume during pregnancy or with third trimester serum ferritin concentration. CONCLUSIONS--These data do not support the proposed association between poor maternal nutrition and increased placental ratio. The association between high placental ratio and adult hypertension may be confounded by genetic and environmental factors associated with maternal obesity (and possibly maternal hypertension).     

Molecular weight variation among bacterial flagellins.

The molecular weights of flagellins from 29 bacterial strains from 11 genera were investigated using the technique of polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. The molecular weights range from 28,600 for Bacillus sphaericus to 63,200 for one strain of Escherichia coli. Variation in molecular weight was observed not only between genera but also between different species of a genus and different strains of a species.     

Cross-sectional growth standards for captive baboons: II. Organ weight by body weight

We present the first cross-sectional organ weight by body weight reference standards for captive baboons (Papio hamadryas). Organ weight data were obtained from necropsy reports for 634 healthy, pedigreed, captive female and male baboons. From summary statistics we calculated and fit cross-sectional sex-specific percentile curves for: adrenals, brain, eyes, heart, kidneys, liver plus gall bladder, lungs, pancreas, pituitary gland, spleen, and thyroid gland in three kilogram body weight intervals and cross-sectional summary statistics by sex for each organ in one kilogram body weight intervals.