title: Effects of longitudinal body mass index variability on microvasculature over 5 years in adult Chinese.
abstract: OBJECTIVE
  To explore the associations of 5-year trend and fluctuation in body mass index (BMI) with retinal vascular caliber in a middle-aged and elderly Chinese population.
  
  
  METHODS
  Participants age ≥40 years were recruited in a prospective study. Baseline BMI data were collected in 2008, and the participants were re-examined annually until 2012. Retinal vascular caliber was measured from fundus photographs collected in 2012. BMI trend was calculated as the slope of BMI against the time of examinations. BMI fluctuation was defined as the root mean square error around the regression line of BMI over time (BMI RMSE) and the coefficient of variation of BMI (BMI CV).
  
  
  RESULTS
  Rising BMI trend was associated with narrower retinal arteriolar and wider venular calibers in the overall subjects, especially among persons with overweight and obesity (BMI ≥ 25 kg/m(2) , P = 0.004 and 0.033, respectively). Rising BMI trend was also significantly associated with narrower retinal arteriole even in nonobese individuals with BMI < 25 kg/m(2) (P = 0.017) when eliminating the effects of hypertension and diabetes. Neither BMI RMSE nor BMI CV was statistically associated with retinal vascular caliber (all P > 0.05).
  
  
  CONCLUSIONS
  Annual rising trending BMI was associated with retinal microvascular alteration. The results suggest that weight gain probably increases the risk of cardiovascular diseases among middle-aged and elderly people.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Gong
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Ophthalmology, Guangzhou No.11 People's Hospital, Guangzhou, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yuetao
authors.initials: Y
authors.lastname: Li
authors.affiliation: Brien Holden Vision Institute, Sydney, New South Wales, Australia.
authors.forename: Brien A
authors.initials: BA
authors.lastname: Holden
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, China.|Department of Ophthalmic Epidemiology, Centre for Eye Research Australia, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Mingguang
authors.initials: M
authors.lastname: He
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000503:physiopathology; D002681:China / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000503:physiopathology*; D011446:Prospective Studies; D012171:Retinal Vessels / Q000503:physiopathology