Glycaemic control in type 2 diabetes: the impact of body weight, β‐cell function and patient education

• Published in: QJM : An International Journal of Medicine Vol. 93; no. 3; pp. 183 - 190
• Main Authors: CHAN, W.B., CHAN, J.C.N., CHOW, C.C., YEUNG, V.T.F., SO, W.Y., LI, J.K.Y., KO, G.T.C., MA, R.C.W., COCKRAM, C.S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-03-2000
• Subjects: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Biological and medical sciences; Blood Glucose - metabolism; Blood Glucose Self-Monitoring; Blood Pressure; Body Weight; C-Peptide - blood; Cross-Sectional Studies; Diabetes Mellitus, Type 2 - metabolism; Diabetes Mellitus, Type 2 - pathology; Diabetes Mellitus, Type 2 - therapy; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Female; Glycated Hemoglobin A - analysis; Humans; Hypoglycemic Agents - therapeutic use; Insulin - therapeutic use; Insulin Resistance; Islets of Langerhans - metabolism; Male; Management. Various non-drug treatments. Langerhans islet grafts; Medical sciences; Middle Aged; Multivariate Analysis; Patient Education as Topic; Endocrinopathy; Biometrics; Human; Biochemical analysis; Hemoglobin A1; Non insulin dependent diabetes; C-Peptide; Biological monitoring; Feeding; Body mass index; Relation; Diet; Education; Cohort study
• ISSN: 1460-2725; 1460-2393; 1460-2393
• DOI: 10.1093/qjmed/93.3.183

We examined the determinants of glycaemic control in a consecutive cohort of 562 newly‐referred Chinese type 2 diabetic patients (57% women) during a 12‐month period. All patients underwent a structured assessment with documentation of clinical and biochemical characteristics. Pancreatic β‐cell function was assessed by fasting plasma C‐peptide concentration. Insulin deficiency was defined as fasting plasma C‐peptide <0.2 pmol/ml. Insulin resistance (IR) was calculated using the homeostasis model assessment (HOMA) based on a product of fasting plasma glucose and insulin concentrations. Treatment was considered appropriate when insulin‐deficient patients were treated with insulin and non‐insulin‐deficient patients were treated with oral agents or diet. Mean (±SD) age was 54.3±13.8 years (range 17–87 years) and disease duration was 5.0±5.9 years. At the time of referral, 70.5% (n=396) were on drug therapy (9% on insulin and 62.8% on oral agents), 20.6% (n=116) were on diet and 9% (n=50) had not received any form of treatment. The mean HbAlc was 8.4±2.3%. The geometric mean (×/÷ antilog SD) of IR was 4.62×/÷2.51 (range 0.63–162.7) and correlated only with waist : hip ratio (WHR, p=0.008). The geometric mean of plasma C peptide was 0.47×/÷2.89 nmol/l and correlated with BMI (p<0.001). Glycated haemoglobin was correlated positively with age (p=0.013), disease duration (p<0.001), IR (p<0.001) and negatively with BMI (p<0.001). Glycated haemoglobin was lower in patients who had seen a dietitian (7.9% vs. 8.7%, p<0.001) or diabetes nurse (7.8% vs. 8.7%, p<0.001) or who performed self blood glucose monitoring (7.9% vs. 8.6%, p=0.001) and higher among smokers (8.9% vs. 8.2%, p=0.003). Compared to insulin‐deficient patients (n=118), non‐insulin‐deficient patients (n=413) had features resembling that of the Metabolic Syndrome with increased WHR (p=0.005), blood pressure (p<0.001), BMI (p=0.001) and were older (p=0.04). Amongst the insulin‐deficient patients, 27% were treated with oral agents or diet. Patients receiving appropriate therapy (n=362) had a lower HbAlc than those treated inappropriately (n=173) (8.2% vs. 8.7%, p=0.02). On multivariate analysis, short disease duration (p<0.001), low IR (p<0.001), high BMI (p=0.001), diabetes education (p<0.001), lack of smoking (p=0.014) and choice of appropriate treatment (p=0.009) were the independent determinants of good glycaemic control.