Strangely the original study misstates the direction of the main finding, contradicting itself directly.
Is this a typo, or something more nefarious?
From the abstract:
Multiple regression analyses revealed that individuals with higher AIS scores had higher daily potassium intake
Multiple regression analysis indicated that individuals with a higher potassium intake had lower AIS scores.That is true. From section 2.6 of the full-text:
> The sleep disturbances were assessed using the Athens Insomnia Scale [ 19], a self-administered psychometric questionnaire designed to evaluate sleep disorders, particularly insomnia [ 20 ]. It consists of eight items rated on a Likert scale ranging from 0 “no problem at all” to 3 “very severe” [ 20]. The total score ranges from 0 (absence of any sleep-related problems) to 24 (the most severe degree of insomnia). Severity is classified as normal for scores of 3 or less, subclinical insomnia for scores of greater than 3 but less than 6, and clinical insomnia for scores of 6 or more [19,21,22].
The contradiction is more clear when comparing the abstract:
> [...] Results: Multiple regression analyses revealed that individuals with higher AIS scores had higher daily potassium intake; potassium at dinner was especially crucial. [...]
and section 3.2:
> 3.2. Association Between AIS Score and Dietary Patterns of Sodium and Potassium > Multiple regression analysis was conducted to investigate the association between AIS scores and dietary patterns of sodium and potassium intake (Table 3). Total daily potassium intake was inversely associated with log AIS score (β = −0.036; p = 0.034). When intake at each meal (breakfast, lunch, dinner, and snacks) was analyzed separately, only potassium intake at dinner remained significantly associated with AIS score (β = −0.066; p = 0.003), suggesting that higher potassium intake at dinner may be linked to fewer sleep disturbances. No significant associations were observed for the sodium-to-potassium ratio.
I'd trust table 3 and the general sentiment of the paper?