title: Association between urban life-years and cardiometabolic risk: the Indian migration study.
abstract: Urban living is associated with an increase in cardiometabolic risks, but the speed at which these risks are accrued over time is unknown. Using a cross-sectional sibling-pair design, the authors surveyed migrant factory workers and their spouses from 4 cities in India together with their rural-dwelling siblings and examined the associations between urban life-years and cardiometabolic risk factors. Data on 4,221 participants (39% women; mean age = 41 years) were available (2005-2007). In regression models, a 2-slope pattern for body fat (with a marked shift at 10 years) was found, whereas a common slope could be accepted for other risk factors. In men, the regression coefficients (per decade of urban life) were 2.5% in the first decade and 0.1% thereafter for body fat; 1.4 mm Hg for systolic blood pressure; and 7% for fasting insulin. Age, gender, marital status, household structure, and occupation did not influence the patterns appreciably; however, stronger gradients for adiposity were noted in migrants from lower socioeconomic positions. The findings suggest that body fat increases rapidly when one first moves to an urban environment, whereas other cardiometabolic risk factors evolve gradually. Public health interventions focused on the control of obesity in newer migrants to urban areas, particularly those from lower socioeconomic positions, may be beneficial.
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, United Kingdom. sanjay.kinra@lshtm.ac.uk
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kinra
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Andersen
authors.forename: Yoav
authors.initials: Y
authors.lastname: Ben-Shlomo
authors.forename: Liza
authors.initials: L
authors.lastname: Bowen
authors.forename: Tanica
authors.initials: T
authors.lastname: Lyngdoh
authors.forename: Dorairaj
authors.initials: D
authors.lastname: Prabhakaran
authors.forename: Kolli Srinath
authors.initials: KS
authors.lastname: Reddy
authors.forename: Lakshmy
authors.initials: L
authors.lastname: Ramakrishnan
authors.forename: Ankalmadagu
authors.initials: A
authors.lastname: Bharathi
authors.forename: Mario
authors.initials: M
authors.lastname: Vaz
authors.forename: Anura
authors.initials: A
authors.lastname: Kurpad
authors.forename: George Davey
authors.initials: GD
authors.lastname: Smith
authors.forename: Shah
authors.initials: S
authors.lastname: Ebrahim
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data*