Do socioeconomic factors shape weight and obesity trajectories over the transition from midlife to old age? Results from the French GAZEL cohort study.
BACKGROUND
Obesity is a contemporary epidemic that does not affect all age groups and sections of society equally.


OBJECTIVE
The objective was to examine socioeconomic differences in trajectories of body mass index (BMI; in kg/m(2)) and obesity between the ages of 45 and 65 y.


METHODS
A total of 13,297 men and 4532 women from the French GAZEL (Gaz de France Electricité de France) cohort study reported their height in 1990 and their weight annually over the subsequent 18 y. Changes in BMI and obesity between ages 45 and 49 y, 50 and 54 y, 55 and 59 y, and 60 and 65 y as a function of education and occupational position (at age 35 y) were modeled by using linear mixed models and generalized estimating equations.


RESULTS
BMI and obesity rates increased between the ages of 45 and 65 y. In men, BMI was higher in unskilled workers than in managers at age 45 y; this difference in BMI increased from 0.82 (95% CI: 0.66, 0.99) at 45 y to 1.06 (95% CI: 0.85, 1.27) at 65 y. Men with a primary school education compared with those with a high school degree at age 45 y had a 0.75 (95% CI: 0.51, 1.00) higher BMI, and this difference increased to 1.32 (95% CI: 1.03,1.62) at age 65 y. Obesity rates were 3.35% and 7.68% at age 45 y and 9.52% and 18.10% at age 65 y in managers and unskilled workers, respectively; the difference in obesity increased by 4.25% (95% CI: 1.87, 6.52). A similar trend was observed in women.


CONCLUSIONS
Weight continues to increase in the transition between midlife and old age; this increase is greater in lower socioeconomic groups.
Dugravot
Aline
A
INSERM U1018 Centre for Research in Epidemiology and Population Health, Villejuif, France. aline.dugravot@inserm.fr
Sabia
Séverine
S
Stringhini
Silvia
S
Kivimaki
Mika
M
Westerlund
Hugo
H
Vahtera
Jussi
J
Guéguen
Alice
A
Zins
Marie
M
Goldberg
Marcel
M
Nabi
Hermann
H
Singh-Manoux
Archana
A
D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D005602:France / Q000453:epidemiology; D014943:Global Health; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D009790:Occupations; D012307:Risk Factors; D012923:Social Class; D012959:Socioeconomic Factors; D015430:Weight Gain; D014944:World Health Organization