Associations of the HOMA2‐%B and HOMA2‐IR with progression to diabetes and glycaemic deterioration in young and middle‐aged Chinese

AIMS: Insulin deficiency (ID) and resistance (IR) contribute to progression from normal glucose tolerance to diabetes to insulin requirement although their relative contributions in young‐onset diabetes is unknown. METHODS: We examined the associations of HOMA2 using fasting plasma glucose and C‐peptide in Chinese aged 20–50 years with (1) progression to type 2 diabetes (T2D) in participants without diabetes in a community‐based cohort (1998–2013) and (2) glycaemic deterioration in patients with T2D in a clinic‐based cohort (1995–2014). We defined ID as HOMA2‐%B below median and insulin IR as HOMA2‐IR above median. RESULTS: During 10‐year follow‐up, 62 (17.9%) of 347 community‐dwelling participants progressed to T2D. After 8.6 years, 291 (48.1%) of 609 patients with T2D had glycaemic deterioration. At baseline, progressors for T2D had higher HOMA2‐IR, while in patients with T2D, progressors for glycaemic deterioration had higher HOMA2‐IR and lower HOMA2‐%B than non‐progressors. The non‐ID/IR group and the ID/IR group had an adjusted odds ratios of 2.47 (95% CI: 1.28, 4.94) and 5.36 (2.26, 12.79), respectively, for incident T2D versus the ID/non‐IR group. In patients with T2D, 50% of the ID/IR group required insulin at 6.7 years versus around 11 years in the non‐ID/IR or ID/non‐IR, and more than 15 years in the non‐ID/non‐IR group. Compared with the latter group, the adjusted hazard ratios were 2.74 (1.80, 4.16) in the ID/non‐IR, 2.73 (1.78, 4.19) in the non‐ID/IR and 4.46 (2.87, 6.91) in the ID/IR group (p‐interaction = 0.049). CONCLUSIONS: In young Chinese adults, IR and ID contributed to progression to T2D and glycaemic deterioration.