title: Risk of non-fatal cardiovascular diseases in early-onset versus late-onset type 2 diabetes in China: a cross-sectional study.
abstract: BACKGROUND
  The age of onset of type 2 diabetes is decreasing. Because non-Chinese patients with early-onset type 2 diabetes (defined here as diagnosis at <40 years) have increased risk of vascular complications, we investigated effects of early-onset versus late-onset type 2 diabetes on risk of non-fatal cardiovascular diseases in China.
  
  
  METHODS
  We did a cross-sectional survey using data from the China National HbA1c Surveillance System (CNHSS), including 222,773 Chinese patients with type 2 diabetes in 630 hospitals from 106 cities in 30 provinces of China in 2012. We documented demographic information and clinical profiles. Non-fatal cardiovascular disease was defined as non-fatal coronary heart disease or non-fatal stroke. Prevalence of non-fatal cardiovascular diseases was standardised to the Chinese population in 2011. We did logistic regression analysis to obtain odds ratios (ORs) for the risk of cardiovascular disease in patients with early-onset versus late-onset type 2 diabetes. Because the CNHSS did not contain patients on diet or lifestyle treatment alone, and did not capture information on smoking or lipid or antihypertensive treatment, we validated our findings in another dataset from a cross-sectional, multicentre observational study (the 3B study) of outpatients with type 2 diabetes to confirm that exclusion of patients with diet treatment only and non-adjustment for lipid-lowering and antihypertensive drugs did not introduce major biases in the main analysis.
  
  
  RESULTS
  Of 222,773 patients recruited from April 1, 2012, to June 30, 2012, 24,316 (11%) had non-fatal cardiovascular disease. Patients with early-onset diabetes had a higher age-adjusted prevalence of non-fatal cardiovascular disease than did patients with late-onset diabetes (11·1% vs 4·9%; p<0·0001). After adjustment for age and sex, patients with early-onset type 2 diabetes had higher risk of non-fatal cardiovascular disease than did those with late-onset type 2 diabetes (OR 1·91, 95% CI 1·81-2·02). Adjustment for duration of diabetes greatly attenuated the effect size for risk of non-fatal cardiovascular disease (1·13, 1·06-1·20). Results of the validation study showed that exclusion of patients with diet only and non-adjustment for lipid-lowering and antihypertensive drugs resulted in marginal changes in ORs for risk of non-fatal cardiovascular disease in patients with early-onset versus late-onset type 2 diabetes. Early-onset type 2 diabetes remained associated with increased risk of cardiovascular disease, attributable to longer duration of diabetes.
  
  
  CONCLUSIONS
  Chinese patients with early-onset type 2 diabetes are at increased risk of non-fatal cardiovascular disease, mostly attributable to longer duration of diabetes.
  
  
  BACKGROUND
  Novo Nordisk China (for the China National HbA1c Surveillance System [CNHSS]) and Merck Sharp & Dohme China (for the 3B study).
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Xiaoxu
authors.initials: X
authors.lastname: Huo
authors.affiliation: Department of Endocrinology, People's Hospital of Peking University, Beijing, China.
authors.forename: Leili
authors.initials: L
authors.lastname: Gao
authors.affiliation: Department of Endocrinology, Beijing Hospital, Beijing, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Endocrinology and Metabolism, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Endocrinology, Peking University Shougang Hospital, Beijing, China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Xinyue
authors.initials: X
authors.lastname: Zhi
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Xiuying
authors.initials: X
authors.lastname: Qi
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Research Center of Basic Medical Sciences, Tianjin Medical University, Tianjin, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Endocrinology, The Fourth Military Medical University Xi Jing Hospital, Xi'an, China.
authors.forename: Qiuhe
authors.initials: Q
authors.lastname: Ji
authors.affiliation: Department of Endocrinology, Sichuan University West China Hospital, Chengdu, China.
authors.forename: Xingwu
authors.initials: X
authors.lastname: Ran
authors.affiliation: Department of Endocrinology, Dalian Medical University Affiliated Hospital, Dalian, China.
authors.forename: Benli
authors.initials: B
authors.lastname: Su
authors.affiliation: Department of Nephrology, Fudan University Huashan Hospital, Shanghai, China.
authors.forename: Chuanming
authors.initials: C
authors.lastname: Hao
authors.affiliation: Department of Endocrinology, The General Hospital of Beijing Military Command, Beijing, China.
authors.forename: Juming
authors.initials: J
authors.lastname: Lu
authors.affiliation: Department of Endocrinology, First Hospital of Peking University, Beijing, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Guo
authors.affiliation: VitalStrategic Research Institute, Berwyn, PA, USA.
authors.forename: Hanjing
authors.initials: H
authors.lastname: Zhuo
authors.affiliation: VitalStrategic Research Institute, Berwyn, PA, USA.
authors.forename: Danyi
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology, The General Hospital of Beijing Military Command, Beijing, China.
authors.forename: Changyu
authors.initials: C
authors.lastname: Pan
authors.affiliation: Department of Endocrinology and Metabolism, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Weng
authors.affiliation: Department of Cardiology, People's Hospital of Peking University, Beijing, China.
authors.forename: Dayi
authors.initials: D
authors.lastname: Hu
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China. Electronic address: yangxilin@tmu.edu.cn.
authors.forename: Xilin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Endocrinology, People's Hospital of Peking University, Beijing, China. Electronic address: jiln@bjmu.edu.cn.
authors.forename: Linong
authors.initials: L
authors.lastname: Ji
mesh_terms: D017668:Age of Onset; D000368:Aged; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged