• webprofusion 30 days ago
    What is it they say about correlation?

    I'm not a scientist but in a group of 60 year olds doom-scrolling in bed vs those who just read a book (or even just go to sleep) is it outside the realm of possibly that the former group may be more likely have other aspects to their life that are unhealthy general?

    • Calavar 30 days ago
      That's a very good point. There are lots of potential confounders here. But I also want to point out that this study isn't a shot in the dark for random correlations -- there are theoretical reasons to believe that poor sleep hygiene would increase the risk of diabetes. Cortisol is tightly coupled to the sleep-wake cycle and to blood sugar levels. It is known to be causative of diabetes in certain rare disease (Cushing disease, for example) and strongly associated in garden variety type 2 diabetes. The article passingly references this (but it uses the more general term glucocorticoid).
    • doctorpangloss 29 days ago
      aHR and RR are broadly comparable.

      Key findings from the diabetes study (this one):

          Night light exposure in the 90-100th percentile (brightest nights): aHR = 1.53 [1.32-1.77]
          Night light exposure in the 70-90th percentile: aHR = 1.39 [1.24-1.57]
          Night light exposure in the 50-70th percentile: aHR = 1.29 [1.14-1.46]
      Key findings from N=1 million birth control use impact on depression study (https://scholar.google.com/scholar_lookup?journal=JAMA+Psych...) :

          Combined oral contraceptives: RR = 1.23 [1.22-1.25] for first use of antidepressants
          Progestin-only pills: RR = 1.34 [1.27-1.40] for first use of antidepressants
          Patch (norgestrolmin): RR = 2.0 [1.76-2.18] for first use of antidepressants
          Vaginal ring (etonogestrel): RR = 1.6 [1.55-1.69] for first use of antidepressants
      In my opinion, if you are okay with birth control, you are probably okay with using light at night.
    • hollerith 29 days ago
      Light exposure was measured by a "wristwatch" worn on the dominant hand, so reading a book is going to get coded as more light than smartphone use probably.
    • elric 29 days ago
      We know that sleep is important. We know that light can mess up your sleep. It stands to reason that if it can mess up your important sleep, it can have negative consequences down the line.
    • daveguy 30 days ago
      It also seems the sample size was so large that it could easily convert these differences into a significant p-value. Is there a statistical compensation to make confounding factor adjustment more stringent with larger sample size?
  • shikon7 29 days ago
    It’s interesting that night light exposure is so important, but the much brighter day light seems to have almost no effect.
  • tlb 29 days ago
    I sleep in a light room wearing a mask. So my eyes are dark, but skin gets some light. My understanding is that melatonin is regulated by light through the eyes, so that should count as dark for circadian rhythm purposes. But I’d appreciate any corrections.

    Seems like this study measured it with a wristwatch, which is a poor proxy for either light on the eyes or skin.

  • hollerith 30 days ago
    In this study, day light is defined as light during 07:30–20:30, and night light, 00:30–06:00. They arrived at those definitions by doing a factor analysis.
    • ekianjo 29 days ago
      so what is the time in between?
      • hollerith 29 days ago
        Data from times outside those 2 ranges were ignored, is my guess.
      • bane 29 days ago
  • zx8080 30 days ago
    Would be great to see a study on using LED vs incandescent bulbs in this regard.
    • alfor 29 days ago
      I switched to halogen incandescent at my desk and I feel much better.

      There is something in the LED and neon light that get me dizzy, it might be the spectrum, it might be the flashing at 120hz.

      We also need near infrared light for our mitochondria to work properly and we created an environment devoid of it.

      • LorenPechtel 29 days ago
        A fair number of people seem to be sensitive to flicker that's too fast for conscious perception.
    • teekert 29 days ago
      Would be difficult, because what is led? Is my tuned-to-low-temp Hue bulb the same as a cheap blueish led bulb?
      • fransje26 29 days ago
        Looking at the light spectrum, it's closer to the cheap, blueish led, yes.
    • porkbeer 29 days ago
      Or any limited vs full specturm lighting for that matter. But blue level might be particularly interesting to correlate.
    • htthbjk 30 days ago
      A bit difficult given that incandescent lights stopped being sold 10 years ago.
      • bayindirh 29 days ago
        You can use halogen bulbs if old school incandescent is not sold where you live.
      • normie3000 29 days ago
        They're still available and popular in many countries, often significantly cheaper than LED bulbs.
      • porkbeer 29 days ago
        They are still sold, but now often as 'heaters' or specialty bulbs, when in fact normal, to skirt regulations.