title: Pulmonary Function and Retrobulbar Hemodynamics in Subjects With Type 2 Diabetes Mellitus.
abstract: BACKGROUND
  The primary goals of this study were to evaluate early changes in pulmonary function and retrobulbar hemodynamics and to examine the correlation between these parameters in patients with type 2 diabetes during the preclinical stages of diabetic retinopathy.
  
  
  METHODS
  For the single-time point measurements, 63 subjects with type 2 diabetes without diabetic retinopathy (diabetes group) and 32 healthy subjects (control group) were selected to evaluate any early changes in pulmonary function and retrobulbar hemodynamics and to examine the correlation between these parameters. In the longitudinal follow-up study, 32 subjects who were newly diagnosed with type 2 diabetes were divided into 2 groups according to their resistivity index (≤0.7 and >0.7). Early changes in pulmonary function and retrobulbar hemodynamics were studied in these groups and compared with the previous values.
  
  
  RESULTS
  For the single-time point measurements, the fasting plasma glucose, 2-h postprandial blood glucose, glycosylated hemoglobin A1c, total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels as well as the pulmonary function parameters were significantly higher in the diabetes group than in the control group. The pulmonary function parameters were negatively and significantly correlated with glycosylated hemoglobin A1c and the duration of diabetes. The retrobulbar hemodynamics were positively correlated with glycosylated hemoglobin A1c and diabetes duration; in contrast, the correlation between retrobulbar hemodynamics and glycosylated hemoglobin A1c. In the longitudinal follow-up study, the pulmonary function of the 2 groups categorized by their resistivity index levels indicated that subjects with resistivity index levels ≤0.7 showed significantly better pulmonary function, and the pulmonary function of this group showed improvement and a significantly smaller decrease. The incidence of diabetic retinopathy in the group with resistivity index levels ≤0.7 (9 of 22, 40.9%) was significantly lower than that in the group with resistivity index levels >0.7.
  
  
  CONCLUSIONS
  Pulmonary function and retrobulbar hemodynamics changed during the preclinical stages of diabetic retinopathy. Regulating glycemia may improve retrobulbar hemodynamics in the retrobulbar arteries (ie, central retinal artery, posterior ciliary artery, and arteria ophthalmica). By detecting the retrobulbar resistivity index and the levels of glycosylated hemoglobin A1c, we could predict future changes in pulmonary function during the preclinical stages of diabetic retinopathy as well as the degree of retinopathy. (ClinicalTrials.gov registration NCT02774733.).
authors.affiliation: Department of Endocrinology and Metabolism, Liaoning Provincial Corps Hospital of Chinese People's Armed Police Forces, Shenyang, China.
authors.forename: He
authors.initials: H
authors.lastname: Tai
authors.affiliation: Department of Endocrinology and Metabolism, Liaoning Provincial Corps Hospital of Chinese People's Armed Police Forces, Shenyang, China.
authors.forename: Ming-Yue
authors.initials: MY
authors.lastname: Wang
authors.affiliation: Department of Endocrinology and Metabolism, Liaoning Provincial Corps Hospital of Chinese People's Armed Police Forces, Shenyang, China.
authors.forename: Yue-Ping
authors.initials: YP
authors.lastname: Zhao
authors.affiliation: Department of Endocrinology and Metabolism, Liaoning Provincial Corps Hospital of Chinese People's Armed Police Forces, Shenyang, China.
authors.forename: Ling-Bing
authors.initials: LB
authors.lastname: Li
authors.affiliation: Division of Medical management, Liaoning University of Traditional Chinese Medicine, Shenyang, China.
authors.forename: Xiao-Lin
authors.initials: XL
authors.lastname: Jiang
authors.affiliation: Department of Endocrinology and Metabolic, Tianjin Municipal Corps Hospital of the Chinese People's Armed Police Forces, Tianjin, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Department of Endocrinology and Metabolic, Tianjin Municipal Corps Hospital of the Chinese People's Armed Police Forces, Tianjin, China.
authors.forename: Xiao-Nan
authors.initials: XN
authors.lastname: Lv
authors.affiliation: Department of Endocrinology and Metabolism, Liaoning Provincial Corps Hospital of Chinese People's Armed Police Forces, Shenyang, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Endocrinology and Metabolism, Shenyang the Fourth Hospital of People, Shenyang, China.
authors.forename: Qian-Yan
authors.initials: QY
authors.lastname: Dong
authors.affiliation: Department of Endocrinology and Metabolism, Shenyang the Fourth Hospital of People, Shenyang, China.
authors.forename: Xin-Guang
authors.initials: XG
authors.lastname: Liu
authors.affiliation: Department of Endocrinology and Metabolism, Shenyang the Fourth Hospital of People, Shenyang, China. 270174194@qq.com.
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Kuang
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006439:Hemodynamics; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000503:physiopathology; D012129:Respiratory Function Tests; D012161:Retinal Artery / Q000503:physiopathology; D012164:Retinal Diseases / Q000209:etiology / Q000503:physiopathology*
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: pulmonary function; resistivity index; retrobulbar hemodynamics; type 2 diabetes; ultrasound