by Michael Woodhead  

Young people with type 1 diabetes have haemoglobin levels up to 2g/dl higher than non-diabetic counterparts, researchers have found.  

A study of 652 patients involved in a US clinical trial found that males with diabetes had higher haemoglobin levels (16 vs 15.1g/dl) than their non diabetic counterparts. Likewise, females with diabetes also had had higher levels of haemoglobin (14.1 vs 13.3) than the general population.  

The authors of the US study, published in Diabetes Care (online 16 November), say the elevations in haemoglobin levels are greatest in teenage females, who had levels 2g/dl higher than similarly aged non-diabetic females.  

In their 20 year prospective study, the researchers found that haemoglobin levels in males with diabetes were stable until about the age of 14, when they began to rise gradually, peaking at around 17g/dl at the age of 22.

In females with diabetes, haemoglobin levels rose sharply by 1.6g/dl at the beginning of their teens and remained elevated.  

The study authors say that while low haemoglobin levels are usually associated with adverse events in diabetes, they had often observed high haemoglobin levels.  

They say the changes in haemoglobin levels might be a response to generalized hypoxia secondary to vascuklar disease or a response to the erythropoeitic effects of insulin and testosterone. Intermittent ketosis might lead to increased beta-hydroxy butyrate resulting in higher haemoglobin, they add.  

“These data have potentially important clinical implications, not only for interpreting haemoglobin values in type 1 diabetes, but also for complications, as we have recently reported that high haemoglobin is a risk factor for proliferative retinopathy,” they say.