Evidence for current diagnostic criteria of diabetes mellitus

Table 1 Evolution of diagnostic criteria of diabetes mellitus

	WHO 1965	WHO 1980	WHO 1985	ADA1997WHO 1999	ADA 2003	IEC 2009ADA 2010WHO 2011
IFG	Not defined	Not defined	Not defined	Fasting ≥ 6.11 to < 7 mmol/L and post glucose (if measured) < 11.1 mmol/L	Fasting ≥ 5.5 to < 7 mmol/L and post glucose (if measured) < 11.1 mmol/L	Fasting ≥ 5.5 to < 7 mmol/L and post glucose (if measured) < 11.1 mmol/L or HbA1c (5.7%-6.4%)
IGT	Post glucose 6.11-7.1 mmol/L	Fasting < 8 mmol/L and/or post glucose ≥ 8 to < 11.1 mmol/L	Fasting < 7.8 mmol/L and/or post glucose ≥ 7.8 to < 11.1 mol/L	Fasting (if measured) < 7 mmol/L and post glucose ≥ 7.8 to 11.1 mmol/L	Fasting (if measured) < 7 mmol/L and post glucose 7.8 to 11.1 mmol/L	Fasting (if measured) < 7 mmol/L and post glucose 7.8 to 11.1 mmol/L or HbA1c (5.7%-6.4%)
DM	Post glucose ≥ 7.22 mmol/L	Fasting ≥ 8 mmol/L and/or post glucose ≥ 11.1 mmol/L	Fasting ≥ 7.8 mmol/L and/or post glucose ≥ 11.1 mmol/L	Fasting ≥ 7 mmol/L and/or post glucose ≥ 11.1 mmol/L	Fasting ≥ 7 mmol/L and/or post glucose ≥ 11.1 mmol/L	Fasting ≥ 7 mmol/L or Post glucose ≥ 11.1 mmol/L and/or HbA1c ≥ 6.5%

IFG: Impaired fasting glucose; IGT: Impaired glucose tolerance; DM: Diabetes mellitus; IEC: International Expert Committee; ADA: American Diabetes Association; WHO: World Health Organization; HbA1c: Glycated hemoglobin

Table 2 Longitudinal studies assessing the glycated hemoglobin thresholds for retinopathy

Ref.	Study population characteristics	Assessment of retinopathy	Method of determining cutoff	Cut off
Tsugawa et al[48]	3 yr follow-up; number = 19987 Japanese subjects; age ≥ 21 yr; diabetes not excluded	Nonmydriatic 45° retinal photograph	Test for nonlinearity in multivariate logistic regression models with restricted cubicspline Multivariate logistic regression with categories of HbA1c as independent variable	Possible threshold at HbA1c levels between 6% and 7% 6.5%-6.9%
van Leiden et al[49] Hoorn study	7.9-11.0 yr follow-up; number = 233; age 50-74 yr; analyses in total study group and in subjects without diabetes	Ophthalmoscopy and fundus photography	Logistic model with categories of HbA1c (adjusted for age, sex, hypertension, glucose metabolism category)	No threshold found

HbA1c: Glycated hemoglobin.