Associations of HbA1c and fasting plasma glucose with incident diabetes: Implications for pre-diabetes thresholds in a Japanese population. Issue 6 (December 2016)

• Record Type: Journal Article
• Authors: Nakagami, Tomoko; Tanaka, Yuki; Oya, Junko; Kurita, Moritoshi; Isago, Chisato; Hasegawa, Yukiko; Ito, Arata; Hirota, Naoki; Tsuzura, Reika; Uchigata, Yasuko
• Is Part Of: Primary care diabetes. Volume 10:Issue 6(2016)
• Page Start: 407
• Page End: 414
• Publication Date: 2016-12
• Subjects: HbA1c -- Fasting plasma glucose -- Incidence -- Pre-diabetes -- Diabetes; Diabetes -- Periodicals; 616.462
• DOI: 10.1016/j.pcd.2016.07.006
• Languages: English
• ISSNs: 1751-9918

Abstract

Highlights: Cox's model and change-point analysis identified lower pre-diabetes cut-offs. The lower HbA1c cut-off for pre-diabetes was 5.7% (39 mmol/mol). The lower FPG cut-off for pre-diabetes was 5.5 mmol/L. Our data support internationally/nationally recommended cut-offs for pre-diabetes. Abstract: Aims: This study assessed pre-diabetes (pre-DM) cutoffs for HbA1c and fasting plasma glucose (FPG) that were associated with an increased risk of incident DM. Methods: We evaluated 2267 non-diabetic Japanese health-check examinees (HbA1c: <6.5% [<48 mmol/mol] and FPG: <7.0 mmol/L) who were 30–79 years old and were followed-up for 5 years. Incident DM was defined as HbA1c of ≥6.5% (≥48 mmol/mol), FPG of ≥7.0 mmol/L, or physician-diagnosed DM. Results: During 11047 person-years, we identified 99 incident DM cases (4.3%). The incidence of DM increased with increasing baseline HbA1c or FPG levels, and the change points (95% confidence intervals) were 5.7% (5.6–5.7%; 39 mmol/mol [38–39 mmol/mol]) for HbA1c and 5.5 mmol/L (5.5–5.6 mmol/L) for FPG. The adjusted hazard ratios (HRs) for incident DM per one standard deviation-increase in HbA1c and FPG were 5.5 (4.4–6.8) and 4.0 (3.2–4.8), respectively. The adjusted HRs for incident DM were significantly higher at HbA1c of 5.7–6.4% (39–46 mmol/mol) or FPG of 5.5–6.9 mmol/L, compared to HbA1c of <5.7% (<39 mmol/mol) or FPG of <5.5 mmol/L. Conclusion: The lower cut-offs for pre-DM may be 5.7% (39 mmol/mol) for HbA1c and 5.5 mmol/L for FPG in this Japanese population.