Plasma Lithium Levels in a General Population: A Cross-Sectional Analysis of Metabolic and Dietary Correlates.

Romina Di Giuseppe,Urte Klink,Katharina Weber,Ilka Ratjen,Manja Koch,Marc Birringer,Janna Enderle,Ulrike Seidel,Gerald Rimbach,Wolfgang Lieb

doi:10.3390/nu12082489

Abstract

Initial evidence suggests that lithium might affect life expectancy and the risk for different disease conditions, but most studies were conducted in patients on lithium medication. Little is known about the association of blood lithium levels within the physiological range with cardiometabolic risk factors and diet. We measured plasma lithium in a community-based sample from Northern Germany (samples taken between 2010 and 2012). All participants (aged 25–82 years) underwent standardized examinations and completed a semi-quantitative food frequency questionnaire. Of several variables tested, the estimated glomerular filtration rate (eGFR) was statistically significantly (inversely) associated with lithium levels, mainly in individuals with slightly impaired renal function (eGFR < 75 mL/min/1.73 m2). Besides, lithium levels were positively associated with age and alcohol intake. Using reduced rank regression, we identified a dietary pattern explaining 8.63% variation in plasma lithium levels. Higher lithium levels were associated with higher intakes of potatoes, leafy vegetables, root vegetables, fruits, tea, beer, wine and dietetic products and lower intakes of pasta, rice, pork, chocolate, sweets, soft drinks, other alcoholic beverages, sauces and snacks. Our observations suggest that plasma lithium levels are associated inversely with kidney function, particularly in individuals with slightly impaired renal function, and positively with age and alcohol intake. Lithium at physiological levels was moderately related to an exploratory dietary pattern.

Highlights

Lithium is an alkali metal in the Earth’s surface [1,2]
After the exclusion of one participant on lithium medication, the final sample consisted of 928 participants, which was used to study the association of lithium plasma levels with different sample characteristics
As some investigations reported seasonal differences in circulating lithium levels in psychiatric patients on lithium medication [63,64], we looked at seasonal variation in our sample

Summary

Introduction

Lithium is an alkali metal in the Earth’s surface [1,2]. Due to its high reactivity, it does not naturally occur in elemental but usually in ionic form (e.g., as lithium chloride, lithium hydroxide or lithium carbonate) [1,3,4]. Lithium is present in trace amounts (7–200 μg/g) in soil and virtually all rocks [1]. The trace element lithium is absorbed in the intestinal tract and is typically present in all human organs and tissues, distributed in aqueous body fluids and is excreted by the kidneys [1,2]. A recent investigation into the bioavailability of lithium from mineral waters with different lithium content reported that the consumption of these waters resulted in a dose-dependent response in serum lithium concentrations and total urinary lithium excretion [9]. A total lithium intake of up to 10 mg/day has shown no adverse effects on human health [4]

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Conclusion