HbA1c (IFCC)

Elevated IFCC HbA1c signals prolonged high blood sugar, contributing to long-term diabetes-related complications. Lifestyle factors affecting levels include diet (reducing added sugars and refined carbs, increasing fiber and lean protein intake), regular exercise, maintaining a healthy weight, good sleep hygiene, and stress reduction. Monitoring IFCC HbA1c helps track glucose control and supports early interventions to reduce health risks.

Most adults benefit from one HbA1c screening test per year. If you're managing a glycemic concern such as pre-diabetes, diabetes, or actively working on insulin sensitivity, retest every three to six months.

At baseline / for screening: Once every 12 months from age 30 as part of a cardiometabolic check. More frequently, every 3 to 6 months, if you have pre-diabetes, type 2 diabetes, polycystic ovary syndrome, or a family history of any of these.

When monitoring an intervention or change: Retest 8 to 12 weeks after a sustained lifestyle change, such as reducing refined carbs and added sugars, increasing physical activity, meaningful weight loss, or improving sleep quality. The same window applies after starting or adjusting glucose-lowering medication (metformin, GLP-1 receptor agonist, SGLT2 inhibitor). If a result was above target, reconfirm sooner once you've begun addressing the most likely driver.

Note: Iron deficiency, recent transfusion, hemoglobinopathies, and stage 4 to 5 CKD distort HbA1c. In those situations, retest more frequently using fasting glucose or fructosamine (which reflects 2 to 3 weeks of glucose) while the underlying condition is addressed.