Table 2.

Glucose homeostasis and diabetes mellitus [76].

		Hyperglycaemia
		Prediabetes		Diabetes mellitus
Type of diabetes	Normal glucose tolerance	Impaired fasting glucose or impaired glucose tolerance	Not insulin requiring	Insulin required for control	Insulin required for survival
Type 1
Type 2
Specific types
Gestational diabetes
Time (years)
Fasting plasma glucose	<5.6 mmol/L (100 mg/dL)	5.6–6.9 mmol/L (100–125 mg/dL)		≥7.0 mmol/L (126 mg/dL)
2-hour plasma glucose	<7.8 mmol/L (140 mg/dL)	<7.8–11.0 mmol/L (140–199 mg/dL)		≥11.1 mmol/L (200 mg/dL)
A1c	<5.6%	5.7–6.4%		≥6.5%

Source: Powers et al. Harrison's principles of internal medicine, 20^th ed., 2018.