Magnesium glycinate: Wang et al., 2026
In 12,328 U.S. adults from the NHANES dataset, higher magnesium depletion scores, a composite of diuretic use, kidney function, and alcohol intake, were associated with 19% increased odds of circadian syndrome, a cluster condition including metabolic dysfunction, depression, and short sleep. This is a cross-sectional analysis, meaning it cannot establish cause, only correlation.
Key takeaways
- Magnesium depletion score (MDS), a calculated risk index, not a direct measurement of tissue magnesium, correlated with circadian syndrome in a dose-response pattern across 12,328 adults.
- Participants with the highest MDS had 19.3% higher odds of circadian syndrome compared to those with the lowest scores, after adjusting for age, sex, race, income, and smoking.
- Body mass index mediated roughly 32% of the association, suggesting weight is part of the pathway linking magnesium status and circadian disruption.
- This is a cross-sectional study, it captures a snapshot in time, so it cannot prove magnesium depletion causes circadian syndrome. Reverse causation is equally plausible: poor sleep and metabolic dysfunction could drive magnesium loss.
- The study used a surrogate endpoint, a calculated score rather than direct tissue magnesium measurement, which introduces uncertainty about what is actually being measured.
The study
Wang et al., Science Progress, 2026. The authors analyzed 12,328 adults from NHANES 2005-2018, a nationally representative U.S. health survey. Mean age was 47 years; 48% were men. This was a cross-sectional retrospective analysis, participants were assessed once, and researchers looked backward at their data to find patterns.
The magnesium depletion score (MDS) was calculated from three inputs: diuretic or proton pump inhibitor use (medications that deplete magnesium), estimated glomerular filtration rate (kidney function, which affects magnesium retention), and alcohol consumption (which increases urinary magnesium loss). Scores ranged from 0 to 5, with higher scores indicating greater depletion risk.
Circadian syndrome was defined as meeting metabolic syndrome criteria (central obesity, high blood pressure, elevated glucose or triglycerides, low HDL) plus at least one of: depressive symptoms or sleep duration under 6 hours per night. The authors used weighted logistic regression to model the association between MDS and circadian syndrome, adjusting for demographic and lifestyle variables. They also ran a mediation analysis to estimate how much of the association was explained by body mass index.
How to read this study
What this paper does well: The sample size is large and nationally representative, which strengthens external validity, the findings likely reflect the broader U.S. adult population. The authors adjusted for multiple confounders including age, race, income, smoking, and physical activity. The mediation analysis is methodologically sound, quantifying BMI's role in the pathway. The dose-response pattern they found, higher MDS, higher circadian syndrome risk, is stronger evidence than a simple binary comparison.
What this paper is missing: The magnesium depletion score is a surrogate endpoint, not a direct measure of tissue magnesium. We have no serum magnesium, red blood cell magnesium, or intracellular magnesium data. The score relies on proxies (medication use, kidney function, alcohol intake) that may or may not reflect true depletion. The cross-sectional design is the bigger limitation, we cannot tell whether magnesium depletion precedes circadian syndrome or vice versa. People with poor sleep and metabolic dysfunction may be more likely to use diuretics, drink alcohol, or have declining kidney function. Reverse causation is entirely plausible.
How I weight this paper: I treat this as hypothesis-generating, not actionable. It flags magnesium as a plausible factor in circadian and metabolic health, but it does not establish that correcting magnesium deficiency would improve sleep or metabolic outcomes. For that, we would need a randomized controlled trial where one group receives magnesium supplementation and the other receives placebo, with sleep and metabolic endpoints measured prospectively. This paper tells us there is an association worth investigating, nothing more.
What they found
Among 12,328 participants, 24.3% met criteria for circadian syndrome. The median magnesium depletion score was 1. After adjusting for age, sex, race, income, education, marital status, smoking, and physical activity, each 1-point increase in MDS was associated with 19.3% higher odds of circadian syndrome (OR = 1.193, 95% CI: 1.099-1.295).
When participants were divided into tertiles by MDS, those in the highest tertile had 38% higher odds of circadian syndrome compared to the lowest tertile (OR = 1.38, 95% CI: 1.17-1.63). The relationship held across all subgroups analyzed: men and women, all age groups, and across racial and ethnic categories.
Mediation analysis found that body mass index accounted for approximately 32% of the total association between MDS and circadian syndrome. This suggests that magnesium depletion may influence circadian health partly through effects on body weight, though the majority of the association (68%) was independent of BMI.
Restricted cubic spline analysis showed a linear dose-response pattern, no threshold effect. Risk increased steadily as MDS rose, with no apparent floor or ceiling.
What it means for the average man
If you take diuretics, use proton pump inhibitors regularly, drink heavily, or have declining kidney function, your magnesium status may be compromised. This study suggests that magnesium depletion, measured indirectly, is associated with a cluster of problems including metabolic dysfunction, depression, and short sleep.
The practical takeaway is not to start supplementing magnesium based on this paper alone. The study does not prove supplementation would reverse circadian syndrome. But if you fit the high-risk profile (medication use, alcohol intake, poor kidney function), checking serum magnesium and considering magnesium-rich foods, leafy greens, nuts, seeds, whole grains, is reasonable. Magnesium glycinate is the form most commonly used for sleep support, but this study did not test supplementation.
The BMI mediation result suggests that managing body weight may be part of the equation. Magnesium depletion, excess weight, and circadian disruption may reinforce one another in a feedback loop.
The caveats
The magnesium depletion score is not a direct measure of magnesium levels. It is a calculated risk index. Someone with a high score may have normal tissue magnesium; someone with a low score may be deficient. The cross-sectional design means we cannot infer causation. It is equally possible that circadian syndrome drives magnesium loss through poor diet, medication use, or metabolic stress.
The definition of circadian syndrome is relatively new and not universally accepted. Some components, particularly the depression criterion, are self-reported and subject to recall bias. Sleep duration was also self-reported, which is less reliable than actigraphy or polysomnography.
No conflicting research is cited because circadian syndrome is a recently defined construct. The study was not industry-funded; the authors declared no conflicts of interest.
Frequently asked questions
Should I trust a cross-sectional study like I would an RCT?
No. A cross-sectional study captures a snapshot in time, it can show that two things occur together, but it cannot prove one causes the other. An RCT randomizes participants to treatment or placebo and follows them forward, which allows you to infer causation. Cross-sectional studies are useful for generating hypotheses and identifying associations worth testing in trials, but they cannot establish that changing one variable (like magnesium status) will change another (like sleep or metabolic health).
What is a surrogate endpoint, and why does it matter?
A surrogate endpoint is a marker used in place of a direct clinical outcome. In this study, the magnesium depletion score is a surrogate, it estimates magnesium deficiency risk based on medication use, kidney function, and alcohol intake, but does not measure actual tissue magnesium. Surrogate endpoints are faster and cheaper to assess, but they introduce uncertainty. A high score may not mean true deficiency, and a low score may miss it. Direct measurement, serum or red blood cell magnesium, would be stronger evidence.
Does this study prove magnesium supplementation will improve my sleep?
No. The study shows an association between magnesium depletion risk and circadian syndrome, but it does not test whether supplementing magnesium reverses the syndrome or improves sleep. That would require a randomized controlled trial where participants are given magnesium or placebo and sleep outcomes are measured. This paper flags magnesium as a plausible factor worth investigating further, but it does not provide evidence that supplementation works.
What is reverse causation, and could it explain these results?
Reverse causation means the direction of cause and effect is backward from what you expect. In this study, it is possible that circadian syndrome, poor sleep, metabolic dysfunction, depression, causes magnesium depletion rather than the other way around. People with circadian syndrome may eat poorly, drink more alcohol, or take medications that deplete magnesium. A cross-sectional design cannot distinguish which came first. Only a prospective trial where magnesium status is manipulated can answer that question.
Sources
- Wang Y., Wu J., Zhang Y., Yu P., Wen G., Li K., et al. Magnesium depletion score and circadian syndrome: Mediated by body mass index. Science Progress. 2026. PubMed
- Nielsen FH. Magnesium deficiency and increased inflammation: current perspectives. Journal of Inflammation Research. 2018;11:25-34.
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