5 research outputs found
The relationship between body size and mortality in the linked Scottish Health Surveys: cross-sectional surveys with follow-up
Objective: To investigate the relationship between body mass index (BMI), waist circumference (WC) or waistβhip ratio (WHR) and all-cause mortality or cause-specific mortality.
Design: Cross-sectional surveys linked to hospital admissions and death records.
Subjects: In total, 20β117 adults (aged 18β86 years) from a nationally representative sample of the Scottish population.
Measurements: Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause, or cause-specific, mortality. The three anthropometric measurements BMI, WC and WHR were the main variables of interest. The following were adjustment variables: age, gender, smoking status, alcohol consumption, survey year, social class and area of deprivation.
Results: BMI-defined obesity (greater than or equal to30βkgβmβ2) was not associated with increased risk of mortality (HR=0.93; 95% confidence interval=0.80β1.08), whereas the overweight category (25β<30βkgβmβ2) was associated with a decreased risk (0.80; 0.70β0.91). In contrast, the HR for a high WC (mengreater than or equal to102βcm, womengreater than or equal to88βcm) was 1.17 (1.02β1.34) and a high WHR (mengreater than or equal to1, women≥0.85) was 1.34 (1.16β1.55). There was an increased risk of cardiovascular disease (CVD) mortality associated with BMI-defined obesity, a high WC and a high WHR categories; the HR estimates for these were 1.36 (1.05β1.77), 1.41 (1.11β1.79) and 1.44 (1.12β1.85), respectively. A low BMI (<18.5βkgβmβ2) was associated with elevated HR for all-cause mortality (2.66; 1.97β3.60), for chronic respiratory disease mortality (3.17; 1.39β7.21) and for acute respiratory disease mortality (11.68; 5.01β27.21). This pattern was repeated for WC but not for WHR.
Conclusions: It might be prudent not to use BMI as the sole measure to summarize body size. The alternatives WC and WHR may more clearly define the health risks associated with excess body fat accumulation. The lack of association between elevated BMI and mortality may reflect the secular decline in CVD mortality.</p