During my annual pilgrimage to the American Academy of Sleep Medicine’s meeting (in Boston this year), I had a high number of revelations and insights. Here are 10 of the most interesting findings and observations:
- Esophageal manometry (measuring pressure levels within the esophagus) is easy to do and is done routinely in Dr. Simmon’s sleep lab. Click here to see his poster. This is probably the gold standard way of diagnosing upper airway resistance syndrome (UARS).
- Cortisol inhibits cancer surveillance genes/processes. Stress (and cortisol) leads to decreased cytotoxic T-cell and natural killer cell activities.
- Sympathetic activity increases vascular endothelial growth factor (VGEF), which is a common biochemical signal that increases tumor growth in many cancers.
- Sleep disruption to mice at 60 times per hour resulted in 25% damage to the brain’s orexin cells (the areas that’s damaged in narcolepsy) and 50% damage to the locus coeruleus in the brain (which makes norepinephrine, one of the neurotransmitters that regulate wakefulness).
- In mice with disrupted circadian rhythms, feeding them dextran sulfate sodium (DSS) caused significant weight loss. Control groups with normal sleep had no weight loss. DSS damages the intestinal lining and causes leakiness. It’s used to cause colitis in mice for research studies.
- Fecal short chain fatty acids were found to be lower with sleep deprivation and/or disruption. Certain highly fermenting bacteria degrade plant fibers, creating short chain fatty acids.
- In humans, major shifts in classes of bacteria with sleep restriction caused an increased the ratio of Firmicutes to Bacteroidetes and lower actinobacteria levels. Some studies report this similar increased ratio in obesity. They also found that participants were 20% less sensitive to inulin after sleep loss.
- Eating lots of fruits and vegetables raises your level of conjugated lineolic acid. Chronic sleep fragmentation was found to lower bifidobacteria. Bifidobacteria has been shown to convert linoleic acid (typically found in common cooking oils) into conjugated linoleic acid (which has been found to surpress chemically induced cancer in mice).
- Shift work in humans leads to weight gain.
- Tai Chi was relatively equivalent to CBT-i in lowering a marker of inflammation, CRP.
The other rewarding part of this conference was the sheer number of interesting people and old friends that I met. Amongst them was Dr. Stasha Gominak (see photo above), whose interview with me about vitamin D is my most popular podcast.
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2. Tonello, Cristina, et al. “Role of sympathetic activity in controlling the expression of vascular endothelial growth factor in brown fat cells of lean and genetically obese rats.” FEBS letters 442.2 (1999): 167-172.
3. Poroyko, Valeriy A., et al. “Chronic sleep disruption alters gut microbiota, induces systemic and adipose tissue inflammation and insulin resistance in mice.” Scientific reports 6 (2016).
4. Christian Benedict, Heike Vogel, Wenke Jonas, Anni Woting, Michael Blaut, Annette Schürmann, Jonathan Cedernaes. Gut Microbiota and Glucometabolic Alterations in Response to Recurrent Partial Sleep Deprivation in Normal-weight Young Individuals. Molecular Metabolism, 2016
5. Suwazono, Yasushi, et al. “A longitudinal study on the effect of shift work on weight gain in male Japanese workers.” Obesity 16.8 (2008): 1887-1893.
6. Irwin, Michael R., et al. “Cognitive behavioral therapy and tai chi reverse cellular and genomic markers of inflammation in late-life insomnia: A randomized controlled trial.” Biological psychiatry 78.10 (2015): 721-729.