Comparison of normal fasting and one-hour glucose levels as predictors of future diabetes during a 34-year follow-up

Figures & data

Figure 1. Cumulative incidence of diabetes during 34 years of follow- up according to baseline fasting blood glucose in 1974. Unadjusted.

Figure 2. Cumulative incidence of diabetes during 34 years of follow- up according to baseline 1-hour post-load glucose in 1974. Unadjusted.

Table I. Risk ratios for type 2 diabetes among 1,145 men during 34 years of follow-up according to quintiles of normal fasting glucose and 1-hour post-load glucose in 1974.

Fasting blood glucose	Quintile 1 (n = 267)	Quintile 2 (n = 211)	Quintile 3 (n = 217)	Quintile 4 (n = 258)	Quintile 5 (n = 192)
Variable
Fasting blood glucose mmol/L (equivalent plasma glucose)	≤ 4.0 (≤ 4.5)	> 4.0–4.3 (> 4.5–4.8)	> 4.3–4.5 (> 4.8–5.0)	> 4.5–4.7 (> 5.0–5.3)	> 4.7–4.9 (> 5.3–5.5)
Person-years of follow-up	9,078	7,174	7,378	8,772	6,528
Number of incident cases of diabetes (of which register-verified)	12 (4)	22 (17)	23 (17)	28 (19)	23 (18)
Risk ratio, adjusted for age, smoking, and BMI (95% CI)	1	1.90 (0.93–3.85)	1.92 (0.95–3.90)	2.03 (1.02–4.02)	2.22 (1.10–4.50)
Risk ratio for the register-verified cases, adjusted for age, smoking, and BMI (95% CI)	1	4.14 (1.39–12.36)	3.94 (1.31–11.85)	4.04 (1.37–11.97)	4.92 (1.65–14.64)
One-hour blood glucose during oral glucose tolerance test	Quintile 1 (n = 214)	Quintile 2 (n = 256)	Quintile 3 (n = 230)	Quintile 4 (n = 221)	Quintile 5 (n = 224)
Variable
1-hour blood glucose, mmol/L (equivalent plasma glucose)	≤ 5.2 (≤ 5.8)	> 5.2–6.2 (> 5.8–6.9)	> 6.2–7.0 (> 6.9–7.8)	> 7.0–8.2 (> 7.8–9.2)	> 8.2 (> 9.2)
Person-years of follow-up	7,276	8,704	7,820	7,514	7,616
Number of incident cases of diabetes (of which register-verified)	10 (6)	12 (7)	15 (9)	27 (18)	44 (35)
Risk ratio, adjusted for age, smoking, and BMI (95% CI)	1	0.86 (0.45–1.67)	1.55 (0.84–2.84)	2.79 (1.63–4.78)	4.23 (2.49–7.17)
Risk ratio for the register-verified cases of diabetes, adjusted for age, smoking, and BMI (95% CI)	1	0.88 (0.29–2.61)	1.13 (0.39–3.28)	2.40 (0.93–6.14)	4.76 (1.94–11.62)