Lifestyle Mediators of Dysglycaemia in Pregnancy: Towards Novel Strategies for Diabetes Management in Pregnancy

Women with diabetes in pregnancy (i.e., pre-gestational type 1- and type 2- and gestational diabetes mellitus [DIP]), struggle to control glucose levels during pregnancy resulting in high risk of pregnancy complications. Current dietary guidelines and methods using carbohydrate content of meals for achieving and quantifying (postprandial) glucose responses are suboptimal, as personal and physiological factors beyond the characteristics of food have been implicated to play an important role.

This PhD project aimed to: (i) examine (dietary) mediators – including personal, physiological and environmental parameters – of (postprandial) glucose control in DIP, and (ii) examine possible nutritional and lifestyle strategies associated with (postprandial) glucose control in DIP.

Study 1, a systematic review and meta-analysis, found that nutritional supplements, diet, and exercise play a prominent role in the management of gestational diabetes (GDM), improving measures of glycaemia, but evidence for pre-gestational diabetes is lacking. The observational secondary data analysis in study 2 concluded that glycaemia varies across the day, with morning glycaemia demonstrating the greatest level of variability, and that increased dietary protein may assist in improving glucose control in GDM. Study 3 was designed to assess the role of diet as mediator of dysglycaemia throughout pregnancy in pre-gestational diabetes and the moderating effects of personal, physiological and environmental parameters. However, recruitment was delayed with no results yet obtained. Therefore, study 4 was designed and conducted using dietary metabolite data from the Born in Bradford cohort and found that meat consumption could be characterised by a distinct metabolite profile using total self-reported meat-intake as criterion. Future analyses exploring other criteria for identifying a distinct metabolite profile and linking meat intake (a major source of protein) to postprandial glucose response in pregnancy are warranted.

This thesis provided new insights into the factors (e.g., timing and protein intake) driving (postprandial) glycaemia in DIP. Future work should aim to better understand the relationship of these factors to aid in the development of more personalised recommendations for improving DIP management.