Midlife coronary artery calcification risk after gestational diabetes

By Melanie Hinze
Research published in Circulation has found that gestational diabetes (GD) is linked with double the risk of coronary artery calcification (CAC) in middle-age, regardless of whether normoglycaemia is achieved after pregnancy.

The study assessed data from the CARDIA (Coronary Artery Risk Development in Young Adults) study – a US multicentre, community-based prospective cohort of 50% black and 50% white women aged 18 to 30 years. In total, 1133 women without diabetes at baseline were followed up for 25 years from 1986 to 2011.

At follow up, 12.3% of women had had GD. Among these women, 25% were found to have CAC, compared with only 15% of women who did not develop GD.

The risk of CAC in midlife was two-fold higher for women with a history of GD and either normoglycaemia, impaired glucose tolerance or overt diabetes within 15 years after pregnancy. This was compared with women with no history of GD who maintained normoglycaemia after pregnancy.

Associate Professor Sarah Zaman, Academic Interventional Cardiologist at Westmead Hospital and Research Fellow at the University of Sydney said, ‘This is important as we know that gestational diabetes confers an elevated risk of CVD, on top of traditional risk factors, but we don’t have a lot of data yet on coronary artery calcium.’ She added, ‘This is important as a CT scan showing CAC can be a marker of early coronary artery disease.’

Professor Zaman told Medicine Today that this research was important for Australians as we had very high rates of GD and the incidence was increasing. However, currently, GD wasn’t incorporated into our risk prediction models for women. She said this study, on top of many others, suggested this may need to change.

‘It confirms that even if glucose levels are normal, having had GD confers a higher risk of CAC,’ she said.

In addition, she noted that this was occurring in middle-aged women, with an average age of 47 years. ‘So, it’s important to be monitoring these women after pregnancy to instigate primary prevention measures such as lifestyle changes, and to be talking about heart health and CVD risk.’
Circulation 2021; 143: 00-00; doi: 10.1161/CIRCULATIONAHA.120.047320.