New research suggests that the diagnosis threshold for Type 2 diabetes should be lowered in women aged under 50 years, since natural blood loss through menstruation could be affecting their blood sugar management.
It is known that women are on average diagnosed with Type 2 diabetes at a later age than men. In this new study, the authors investigated whether a contributing factor to this late diagnosis may be a sex difference in the levels of glycated haemoglobin (HbA1c – a standard measure of blood sugar control) due to haemoglobin replacement linked to menstrual blood loss.
The study, by Dr Adrian Heald, Salford Royal Hospital, UK, examined HbA1c testing across seven UK laboratory sites (representing 5% of UK population). At age 50 years, average HbA1c levels in women were found to lag by approximately five years compared to men. Further analysis showed that, at HbA1c of 48 mmol/mol, 50% fewer women could be diagnosed with Type 2 diabetes than men under the age of 50, whilst only 20% fewer women could be diagnosed with Type 2 diabetes than men over or equal to the age of 50.
Based on these observations, the authors estimated the effects of lowering the threshold for diagnosis of diabetes from HbA1c (48 mmol/mol) by 4.2% to 46 mmol/mol for women under the age of 50. This analysis showed that an additional 35,345 currently undiagnosed women in England would be reclassified as being diagnosed with Type 2 diabetes (17% more than the current 208,000 recorded women with Type 2 diabetes aged under 50 years). Lifestyle changes and treatment for diabetes would then be initiated for these women enabling improvement in health outcomes over both the short and longer term.