This study looked at roughly 14,000 NHANES III participants that were not diabetic. I think this is an important distinction because it looks at differences in normal range, "free", if you will, of what the frank hyperglycemia associated with metabolic dysfunction might do to mean and/or median values. Here is the hazard ratio plot:
 |
Adjusted hazard ratios for the association between HbA1c and all-cause mortality among participants without diabetes using a quadratic spline with knots at the 2.5, 10, 50, 90, and 97.5 percentiles. Adjusted for age, race-ethnicity, sex, lifestyle factors (education, income, current smoking, alcohol consumption, physical activity, body mass index, and aspirin use), cardiovascular factors (systolic blood pressure, antihypertensive medication use, total cholesterol, HDL cholesterol, log triglycerides, elevated C-reactive protein, and history of CVD), metabolic factors (prior diagnosis of thyroid disease, thyroid-stimulating hormone, estimated glomerular filtration rate, and albuminuria), red blood cell indices (hemoglobin, red blood cell distribution width, mean cell volume, and serum folate), iron storage indices (serum albumin, ferritin, and transferrin saturation), and liver function indices (hepatitis C seropositivity, AST, and ALT). Knots were placed at 4.3%, 4.7%, 5.3%, 5.9%, and 6.2%, representing HbA1c levels at the 2.5, 10, 50, 90, and 97.5 percentiles; shaded area represents 95% CI. |
