The Nutrition Society Cuthbertson Award has been awarded annually since 1990 to scientists or clinicians at an early stage of their career for excellence inclinical nutrition and/or metabolism research providing an evidence base for clinical practice. Congratulations to Dr Giovanna Muscogiuri for winning this prestigious award, which was presented at a ceremony on 24 January 2023 for her work at the intersection of chronotype, sleep impairment and obesity.
Great to meet with you Giovanna.
Please tell us about your current research on the relationship between chronotype, sleep disturbances and cardiometabolic diseases such as obesity
Chronotype is the predisposition of a person to carry out most of his/her daily activities in the first half (person with morning chronotype or “lark”) or in the second part (person with evening chronotype or “owl”) of the day. People who are in an intermediate position between morning and evening chronotypes are categorised as “intermediate chronotype”. It has been observed that patients with evening chronotype are more prone to follow unhealthy lifestyles and to go to sleep late, thus developing sleep disturbances that in turn are risk factors for obesity and obesity-related metabolic diseases.
How does an individual’s chronotype affect their susceptibility to sleep disturbances such as insomnia and sleep apnea?
People with evening chronotype usually have a delay of peak cortisol levels in the morning and thus resulting in waking up later and going to bed later going against the physiological circadian rhythm and predisposing them to insomnia and sleep apnea.
What is the biological mechanism that leads an individual’s chronotype to impact their risk for cardiometabolic diseases such as obesity?
People with evening chronotype have less adherence to healthy lifestyle and are more often sedentary and smokers. All these features make them at risk of developing obesity and cardiometabolic diseases.
People with evening chronotype usually have a delay of peak cortisol levels in the morning and thus resulting in waking up later and going to bed later going against the physiological circadian rhythm and predisposing to insomnia and sleep apnea.
Can you speak to the potential long-term health consequences of untreated sleep disturbances in individuals with specific chronotypes?
Sleep disturbances that mostly occur in people with evening chronotype are able to start a vicious cycle that lead to detrimental long-term consequences. Experimental laboratory studies have demonstrated that decreasing either the amount or quality of sleep increase the risk of developing obesity. Experimental sleep restriction also causes physiological, hormonal and food behavioral changes that promote a positive energy balance and a compensatory disproportionate increase in food intake, decrease in physical activity, and weight gain. All of these factors may increase the long-term risk of developing cardiovascular diseases.
How do chronotype and sleep disturbances interact with other factors such as age, gender, and lifestyle? Can the chronotype of an individual be modified?
Sleep and chronotype change with life-stages and age. We know that sleep architecture changes in pregnancy and during breastfeeding. We also know that people may switch chronotype categories. For example, we reported that post-menopausal women have the tendency to switch to morning chronotype while pre-menopausal women are predominantly intermediate chronotype.
What is the key finding, then, in your research on chronotype and sleep disturbances in relationship to obesity and other cardiometabilic disease?
People with evening chronotype more often develop sleep disturbances which in turn predispose people, through several mechanisms, to weight gain and to obesity-related cardiometabolic diseases.
Can you discuss any clinical applications or implications of your research on chronotype and sleep disturbances?
Since it has been demonstrated that both chronotype categories and sleep quality could have an impact in determining obesity risk, it should be mandatory to assess and to target sleep as part of multidisciplinary obesity management.
How do various treatment approaches, such as light therapy or melatonin supplements, impact chronotype and sleep disturbances? Are there any new treatment approaches on the horizon?
Currently there are no validated therapeutic and nutritional approaches to realign subjects with blunted circadian rhythm. However, there is evidence in animal studies that melatonin and also ketogenic and Mediterranean dietary patterns could show some benefit to patients.
How do you see the field of chronotype and sleep disturbances research evolving?
Our research highlights the need for the evaluation of chronotype categories and sleep quality in the assessment of subjects with obesity. Thus, we expect that in the near future it should be set a nutritional and therapeutic approach targeting circadian rhythm dysfunction as well. This could potentially support the efficacy of current obesity treatments.
Read the full award announcement on the Nutrition Society website: https://www.nutritionsociety.org/announcements/2022-cuthbertson-award-winner-announced-dr-giovanna-muscogiuri