The effects of adiposity and weight change on forced expiratory volume decline in a longitudinal study of adults.
OBJECTIVE
To investigate whether changes in anthropometric measures are related to lung function decline.


METHODS
A national 7-y follow up study in Great Britain.


METHODS
3391 adults aged 18-73 y at baseline.


METHODS
The primary outcome measure was change in forced expiratory volume in one second (Delta FEV1), adjusted for age, height and sex. This was related to changes in weight, body mass index, waist circumference, hips circumference and waist to hip ratio.


RESULTS
Changes in weight, body mass and waist circumference, adjusted for confounders including mean level, were all associated with changes in FEV1 (P<0.001), with all effects stronger in men than women (P<0.05). Change in waist to hip ratio was related in men (P=0.01), but not in women (P=0.34). A 10 kg weight increase induced an additional fall in FEV1 of 96 ml (95% confidence interval (95% CI 65-127 ml) in men, and 51 ml (95% CI. 27-75 ml) in women. In men, the effect increased with average weight and obesity and was more pronounced in middle age. This phenomenon was not present in women, possibly due to gender differences in weight distribution in later adult life. Smoking did not appear to influence the magnitude of effect in either sex. The detrimental effect of weight gain on FEV1 in subjects that stopped smoking between studies appeared small in comparison to the benefit of smoking cessation.


CONCLUSIONS
Increases in adult body mass are predictors of FEV1 decline, especially among older and heavier men, where weight reduction may significantly slow lung function decline.
Carey
I M
IM
Department of Public Health Sciences, St George's Hospital Medical School, London, UK. i.carey@sghms.ac.uk
Cook
D G
DG
Strachan
D P
DP
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000886:Anthropometry; D001824:Body Constitution; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D017678:Sex Distribution; D012737:Sex Factors; D016540:Smoking Cessation; D013147:Spirometry; D006113:United Kingdom; D015430:Weight Gain / Q000502:physiology*