Medical Bulletin 20/ July/ 2024

Rigorous exercise before bed has long been discouraged, but researchers from the University of Otago have discovered that short bursts of light activity can actually improve sleep.

In a groundbreaking study published in BMJ Open Sport & Exercise Medicine, researchers determine if performing regular 3-min bouts of resistance exercise spread over 4 hours in an evening will impact subsequent sleep quantity and quality, sedentary time and physical activity compared with prolonged uninterrupted sitting.

Engaging in short bursts of light activity has numerous benefits for overall health and well-being. Incorporating brief periods of physical activity throughout the day can enhance sleep quality, leading to longer and more restful sleep. Additionally, these small bouts of exercise can improve mood, boost energy levels, and promote better cardiovascular health. Even minimal physical activity can positively impact daily functioning and contribute to a healthier lifestyle.

In this randomized crossover trial, participants took part in two different 4-hour sessions starting at around 5:00 PM. In one session, they sat for the entire 4 hours, and in the other session, they took 3-minute breaks every 30 minutes to do bodyweight resistance exercises. After each session, participants went back to their normal daily routines. This study looked at secondary outcomes like sleep quality and quantity, as well as physical activity and sitting time. These were measured using wrist-worn ActiGraph GT3+ devices and a sleep and activity diary.

The results showed that compared with prolonged sitting, regular activity breaks increased the average sleep period and time spent asleep by 29.3 minutes on the night of the intervention. However, there was no significant effect on average sleep efficiency, wake after sleep onset, or the number of awakenings. Additionally, the physical activity patterns for the following 24-hour and 48-hour periods did not show any significant differences.

“We know that many people sit for long periods in the evening. Our previous studies found that doing 2-3 minutes of exercise every 30 minutes reduces sugar and fat in the blood after meals. While sleep guidelines discourage high-intensity exercise before bed due to its potential negative impact on sleep, our study explored the effects of short bouts of light activity throughout the evening. We discovered that regularly interrupting sitting time with light activity can promote better sleep without the downsides of intense exercise, suggesting a need to review current guidelines,” said the researchers.

Reference: Gale, J. T., et al. (2024). Evening regular activity breaks extend subsequent free-living sleep time in healthy adults: a randomised crossover trial. BMJ Open Sport & Exercise Medicine. doi.org/10.1136/bmjsem-2023-001774.

A recent study published in JAMA revealed that women with ovarian endometriomas or deep infiltrating endometriosis face a significantly heightened risk of developing ovarian cancer.

Endometriosis affects approximately 11% of reproductive-aged women, including 50% to 60% of women and teenage girls experiencing pelvic pain and up to 50% of women with infertility. This condition has been associated with various comorbidities, including ovarian, breast, and endometrial cancers, and impacts mental, menstrual, urinary, bowel, and other nonspecific symptoms.

The study, conducted using data from the Utah Population Database (UPDB), aimed to evaluate the association between endometriosis and ovarian cancer incidence. Researchers developed a retrospective cohort, including women aged 18 to 55 years with at least one diagnosis of endometriosis.

The findings revealed an observed endometriosis prevalence of 6.3%, with categories including superficial peritoneal endometriosis, ovarian endometriomas, deep infiltrating endometriosis, ovarian endometriosis, and concurrent deep infiltrating endometriosis. Women with a history of endometriosis were matched 1:5 with unexposed women.

The study found that all ovarian cancer histotypes were more common in women with endometriosis, with adjusted hazard ratios (aHRs) ranging from 2.70 for high-grade serous ovarian cancer to 11.15 for clear cell carcinoma. Overall, the aHR for ovarian cancer in women with endometriosis was 4.20 compared to those without the condition.

Women with deep infiltrating endometriosis or ovarian endometriomas had the highest risk of ovarian cancer. The aHR for deep infiltrating endometriosis was 18.76, and for concurrent deep infiltrating endometriosis and ovarian endometriomas, it was 13.04. The strongest association was found between these endometriosis subtypes and type 1 ovarian cancer, with an aHR of 18.96. However, all endometriosis subtypes were linked to increased risks of both type 1 and type 2 ovarian cancer.

The study identified an excess risk of ovarian cancer in 9.90 women with endometriosis per 10,000. The overall bias-adjusted hazard ratio was 8.29.

These results underscored the significantly increased risk of ovarian cancer among women with endometriosis, prompting the need for further studies to better understand the biological mechanisms underlying these associations.

Reference: Barnard ME, Farland LV, Yan B, et al. Endometriosis Typology and Ovarian Cancer Risk. JAMA. Published online July 17, 2024. doi:10.1001/jama.2024.9210

A recent study published in the journal Nutrients investigates the association between coffee consumption and polycystic ovarian syndrome (PCOS) in women.

Women with PCOS often face hormonal imbalances leading to ovulatory issues, and are at higher risk for psychological and metabolic disorders such as cardiovascular disease, type 2 diabetes, obesity, insulin resistance, and anxiety. A UK study found that 26% of PCOS patients develop diabetes, adding costs to the NHS. Global prevalence of PCOS varies, with up to 15% of women of reproductive age affected.

PCOS is influenced by genetic, environmental, and epigenetic factors. Women with PCOS typically have poor diets, low in magnesium and zinc, and lead sedentary lifestyles. Lifestyle interventions like diet and exercise have proven effective in managing PCOS symptoms. Specifically, a low-carb diet can reduce glucose and insulin-like growth factor-binding protein 1 (IGFBP1) levels and alleviate hyperandrogenism.

Research has indicated that coffee consumption can improve PCOS symptoms by enhancing insulin sensitivity, reducing hypersecretion, and improving β-cell function through high phenol content and reduced expression of the PI3K pathway.

The study was conducted between September 2014 and May 2016 at the University Clinical Hospital in Spain. It involved diagnosing PCOS using clinical and biochemical tests, including total testosterone levels of 2.6 nmol/L or more for hyperandrogenism (HA), ultrasound images for polycystic ovarian morphology (PCOM), and tests for oligo-anovulation/amenorrhea (OD).

PCOS patients were categorized into four phenotypes:

Phenotype A: HA, OD, and PCOM

Phenotype B: HA and OD

Phenotype C: HA and PCOM

Phenotype D: OD and PCOM

Daily caffeine and alcohol intake was measured using a semi-quantitative food frequency questionnaire (FFQ). The study cohort's average caffeine intake was 52.46 mg/day.

The results showed that drinking at least one cup of coffee daily reduces the risk of PCOS. Women who drank about two cups of coffee daily had a 70% lower risk of developing PCOS symptoms compared to those who never drank coffee. This protective effect of coffee is linked to its influence on the metabolism of sex hormones like testosterone.

The study found that coffee consumption reduces the risk of developing PCOS symptoms in a dose-dependent manner. Coffee's bioactive compounds have anti-inflammatory properties that may regulate hormone levels and improve insulin sensitivity. However, excessive caffeine intake is linked to estrogen-dependent cancers. Further research is needed to confirm these findings and develop a safe, effective coffee-based intervention for PCOS.

Reference: Meliani-Rodriguez, A., Cutillas-Tolin, A., Mendiola, J., et al. (2024) Association between Coffee Consumption and Polycystic Ovary Syndrome: An Exploratory Case–Control Study. Nutrients, 16(14), 2238. doi:10.3390/nu16142238, https://www.mdpi.com/2072-6643/16/14/2238