High dietary selenium intake is associated with less insulin resistance in the Newfoundland population

Abstract

As an essential nutrient, Selenium (Se) is involved in many metabolic activities including mimicking insulin function. Data on Se in various biological samples and insulin resistance are contradictory, moreover there is no large study available regarding the relationship of dietary Se intake with insulin resistance in the general population. To investigate the association between dietary Se intake and variation of insulin resistance in a large population based study, a total of 2420 subjects without diabetes from the CODING (Complex Diseases in the Newfoundland Population: Environment and Genetics) study were assessed. Dietary Se intake was evaluated from the Willett Food Frequency questionnaire. Fasting blood samples were used for the measurement of glucose and insulin. Insulin resistance was determined with the homeostasis model assessment (HOMA-IR). Body composition was measured using dual energy X-ray absorptiometry. Analysis of covariance showed that high HOMA-IR groups in both males and females had the lowest dietary Se intake (μg/kg/day) (p < 0.01), being 18% and 11% lower than low HOMA-IR groups respectively. Insulin resistance decreased with the increase of dietary Se intake in females but not in males after controlling for age, total calorie intake, physical activity level, serum calcium, serum magnesium, and body fat percentage (p < 0.01). Partial correlation analysis showed that dietary Se intake was negatively correlated with HOMA-IR after adjusting for the Se confounding factors in subjects whose dietary Se intake was below 1.6 μg/kg/day (r = -0.121 for males and -0.153 for females, p < 0.05). However, the negative correlation was no longer significant when dietary Se intake was above 1.6 μg/kg/day. Our findings suggest that higher dietary Se intake is beneficially correlated with lower insulin resistance when total dietary Se intake was below 1.6 μg/kg/day. Above this cutoff, this beneficial effect disappears.

Selenium and Polycystic Ovary Syndrome; Current Knowledge and Future Directions: A Systematic Review

“…Being widely used in inflammatory reproductive diseases, Se may inhibit NF-κβ and reduce inflammatory cytokines including TNF-α and IL-1/18, thereby preventing insulin resistance [21,45]. It may be speculated that the systemic inflammatory condition in PCOS negatively influences Se concentration which results in exacerbation of inflammation [46][47][48].…”

Higher toenail selenium is associated with increased insulin resistance risk in omnivores, but not in vegetarians

“…HOMA-IR = FI (mU/L) × FG (mmol/L) / 22.5 [16,19] Insulin resistance is defined as HOMA-IR > 2.60 [18,20].…”

Higher toenail selenium is associated with increased insulin resistance risk in omnivores, but not in vegetarians

“…Several mechanisms may explain how Se affects insulin resistance. Some of such mechanisms include insulin-like action, oxidative stress, and in ammatory cytokines (16). In animal studies, diets rich in Se may promote the release of glucagon causing s hyperglycemia.…”

“…Fasting blood glucose (FG) and fasting insulin (FI) concentrations were tested by the Clinical Laboratory Center of Shanghai Xinhua Hospital. Insulin resistance and b-cell function were evaluated by the homeostasis model assessment (HOMA) method (18), in which FI (mU/L) and FG (mmol/L) were used HOMA-IR= FI (mU/L)×FG (mmol/L) / 22.5 (16,19) Insulin resistance is de ned as HOMA-IR > 2.60 (18,20).…”

“…Insulin resistance is not only a hallmark but also a pathophysiological factor in diabetes (15). A few studies have examined the association between Se levels and insulin resistance, but the research ndings from such studies are contradictory (16,17). Furthermore, no research has evaluated the relationship between Se status and insulin resistance in vegetarians and omnivores.…”