Table 2.
HRs of different combinations of low HDL cholesterol and metformin use for cancer risk in type 2 diabetes
| Exposures | n at risk | HR (95% CI) | P |
|---|---|---|---|
| HDL cholesterol <1.0 vs. ≥1.0 mmol/L |
|||
| Among metformin nonusers |
|||
| Model 1* |
200 |
2.87 (1.57–5.25) |
0.0006 |
| Model 2*† |
200 |
2.99 (1.60–5.61) |
0.0006 |
| Among metformin users |
|||
| Model 3* |
233 |
1.66 (0.72–3.87) |
0.2367 |
| Model 4*† |
233 |
1.61 (0.66–3.92) |
0.2969 |
| Average daily metformin dose in the whole cohort (per g) |
|||
| Model 5*‡ |
1,266 |
0.44 (0.32–0.62) |
<0.0001 |
| Model 6*†‡ |
1,266 |
0.50 (0.35–0.71) |
<0.0001 |
| Metformin users vs. nonusers |
|||
| Among patients with HDL cholesterol ≥1.0 mmol/L |
|||
| Model 7*‡ |
1,033 |
0.46 (0.28–0.74) |
0.0013 |
| Model 8*†‡ |
1,033 |
0.51 (0.31–0.82) |
0.0059 |
| Among patients with HDL cholesterol <1.0 mmol/L |
|||
| Model 9*‡ |
233 |
0.29 (0.13–0.61) |
0.0013 |
| Model 10*†‡ |
233 |
0.30 (0.13–0.70) |
0.0052 |
| Biological interaction models |
|||
| Model 11*‡ |
|||
| HDL cholesterol <1.0 mmol/L plus nonuse of metformin |
200 |
6.18 (3.35–11.40) |
<0.0001 |
| HDL cholesterol ≥1.0 mmol/L plus nonuse of metformin |
1,192 |
2.35 (1.47–3.75) |
0.0003 |
| HDL cholesterol <1.0 mmol/L plus use of metformin |
233 |
1.83 (0.87–3.88) |
0.1140 |
| HDL cholesterol ≥1.0 mmol/L plus use of metformin |
1,033 |
Reference |
|
| Model 12*†‡ |
|||
| HDL cholesterol <1.0 mmol/L plus nonuse of metformin |
200 |
5.75 (3.03–10.90) |
<0.0001 |
| HDL cholesterol ≥1.0 mmol/L plus nonuse of metformin |
1,192 |
2.17 (1.35–3.49) |
0.0013 |
| HDL cholesterol <1.0 mmol/L plus use of metformin |
233 |
2.02 (0.94–4.35) |
0.0855 |
| HDL cholesterol ≥1.0 mmol/L plus use of metformin | 1,033 | Reference |
*Adjusted for LDL cholesterol–related risk indicators (LDL cholesterol ≥3.8 mmol/L and LDL cholesterol <2.8 mmol/L plus albuminuria), HDL cholesterol ≥1.30 mmol/L (not for models 7 and 8), and the nonlinear association of triglycerides with cancer.
†Further adjusted for age, sex, employment status, smoking status, alcohol intake, duration of diabetes, BMI (≥27.6 or <24.0 kg/m2), A1C, and SBP at enrollment and use of statins, fibrates, other lipid-lowering drugs, ACE inhibitors/ARBs, and insulin during follow-up.
‡Stratified Cox model analyses on deciles of the propensity score of metformin use were included in models 5–12 to control for the likelihood of starting metformin therapy during follow-up.