People with type 1 diabetes could lower HbA1c by quitting smoking

People with type 1 diabetes who give up smoking could lower their HbA1c to similar levels as non-smokers with the condition, a US study reports.
Smokers who quit also experienced a reduced risk of vision and kidney-related complications, similar to the risk experienced by non-smokers.
Smoking was linked to increased HbA1c levels and rates of complications, but the findings indicate positive health changes for those with type 1 diabetes who quit smoking.
Researchers from George Washington University examined the health records of 1,441 people from a major, 10-year study called Diabetes Control and Complications Trial (DCCT).
The research team used the analysis to compare with previously studies which had investigated people with type 1 diabetes who quit smoking, and what health impact this had.
The results demonstrated that people who smoked had greater HbA1c levels compared to non-smokers by more than 0.30% points (equivalent to 3 mmol/mol).
Smokers showed a 43% increased risk of retinopathy and a 36% increased risk of kidney complications compared to those who had not smoked before.
But, quitters with type 1 diabetes had HbA1c levels near to those who had not smoked previously, as well as similar complications rates.
The researchers concluded: “Former smokers can achieve similar glycaemic control to never smokers and reduce their risk of complications. The results of this study should be used to encourage individuals with type 1 diabetes to avoid smoking or to quit as soon as possible.”
The findings have been published in the journal PLOS One.