The Essential Element Manganese, Oxidative Stress, and Metabolic Diseases: Links and Interactions

Table 1

The studies of Mn and MetS.

Reference	Country	Study design	Sample size	Data source/sample type	Results
[30]	China	The 5th Chinese National Nutrition and Health Survey (2010–2012)	2111	Questionnaire of dietary Mn intake	Men	A decreased risk of MetS with higher Mn intake.
					Women	An increased risk of MetS with higher Mn intake.
					MetS components	Mn intake was inversely associated with abdominal obesity and hypertriacylglycerolaemia in men, but positively associated with low HDL-cholesterol in both men and women.
[31]	Korea	The Korea National Health and Nutrition Examination Survey (2007–2008)	5136	Questionnaire of dietary Mn intake	Men	No difference
					Women/MetS components	The women subjects with high blood pressure showed significantly lower intake of Mn than did control subjects.
[32]	China	Cross-sectional study	Cases: 221 Controls: 329	Questionnaire of dietary Mn intake	Men/women	A lower risk of developing MetS in the second, third, and highest quintiles of Mn intake with respect to the lowest quintile after adjusting age, sex, and energy intake.
					MetS components	Daily intake of Mn was decreased with the increasing number of MetS components.
[5]	Poland	Cross-sectional study	313 (men aged 50–75 years)	Serum (Mn level)	Significant positive correlations (Mn–BMI, Mn–abdominal circumference, Mn–waist-to-hip ratio, Mn–insulin, Mn–HOMA-IR), but no correlation with MetS.
[33]	Korea	The Korea National Health and Nutrition Examination Survey (2008)	1405	Whole blood (Mn level)	No difference
				Urine (Mn level)	No difference