Age at type 2 diabetes onset, HOMA-derived indices and risks of diabetic retinopathy: a real-world cross-sectional...

The roles of insulin resistance (IR) and β-cell dysfunction in diabetic retinopathy (DR) remain controversial, and whether age at type 2 diabetes mellitus (T2DM) onset modifies these associations is unclear. This study aimed to evaluate the associations of HOMA-IR and HOMA-β with DR risk, stratified by age at diagnosis.

In this real-world cross-sectional study, we analyzed data from 6,996 patients with T2DM from Lishui People's Hospital, China. Participants were categorized by age at onset (<65 vs. ≥65 years) and HOMA indices (HOMA-β <66 vs. ≥66; HOMA-IR <5 vs. ≥5). Multivariable logistic regression was used to assess adjusted odds ratios (aORs) for DR.

A total of 1,360 DR cases were identified in 6996 participants. Low HOMA-β was significantly associated with higher DR odds, especially in the younger-onset group (aOR = 2.97, 95% CI: 2.24-3.99). High HOMA-IR was associated with increased DR odds in younger-onset participants (aOR = 3.14, 95% CI: 2.31-4.33). Notably, among participants with high HOMA-β or low HOMA-IR, age at T2DM onset did not significantly modify the association with DR. Subgroup analyses showed strong associations in those with renal dysfunction or not using lipid-lowering agents.

Both β-cell dysfunction and insulin resistance were independently associated with increased odds of diabetic retinopathy in younger-onset type 2 diabetes. Age at onset significantly modified these associations, supporting age-stratified screening and tailored management strategies.