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- Mazidi, Mohsen, 1989, et al.
(författare)
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Higher Plasma Levels of Valerate Produced by Gut Microbiota May Have a Beneficial Impact on Renal Function
- 2023
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Ingår i: Journal of the American Nutrition Association. - : Informa UK Limited. - 2769-7061 .- 2769-707X. ; 42:6, s. 534-540
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Observational studies have evaluated the relationships among plasma short chain fatty acids (SCFA) produced by gut microbiota, renal function, and risk of chronic kidney disease (CKD). In the present study, Mendelian Randomization (MR) analysis was applied to obtain unconfounded estimates of the casual association of genetically determined plasma valerate (an SCFA) with kidney function and risk of CKD. Method: MR was performed by using summary-level data from the largest genome-wide association studies (GWAS) conducted on plasma valerate, CKD, and estimated glomerular filtration rate (eGFR; separately in diabetic and nondiabetic individuals). Inverse variance weighted method (IVW), weighted median–based method, MR-Egger, as well as MR-Pleiotropy RESidual Sum and Outlier (PRESSO) were applied. Sensitivity analysis was conducted using the leave-one-out method. Results: No significant association was observed between plasma valerate and CKD (IVW: β = 0.234, p = 0.744). In contrast, plasma valerate was positively associated with eGFR in the total population (IVW: β = 0.049, p = 0.022) and among nondiabetic individuals (IVW: β = 0.058, p = 0.009), but not in the diabetic population (IVW: β = −0.052, p = 0.603). None of the estimated associations was subjected to significant level of heterogeneity. Furthermore, MR-PRESSO analysis did not show any chance of outlier for all estimates. The pleiotropy test, with very a negligible intercept and insignificant p value, also indicated no chance of pleiotropy for all of our estimations (all p > 0.539). The results of the MR-Robust Adjusted Profile Score were identical with the IVW estimates, highlighting again no possibility of pleiotropy. Results of the leave-one-out method demonstrated that the links were not driven by single-nucleotide polymorphisms. Conclusions: Individuals with higher plasma valerate levels had better renal function, defined by eGFR. This finding was observed in the total population and in nondiabetic subjects, but not in those with diabetes. Further research is needed to elucidate the links among plasma valerate, kidney function, and CKD.
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| 2. |
- Mazidi, Mohsen, 1989, et al.
(författare)
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Plasma Trans Fatty Acids Concentrations Are Inversely Related to Bone Mineral Density and This Appears to Be Independent of Inflammation
- 2023
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Ingår i: Journal of the American Nutrition Association. - : Informa UK Limited. - 2769-7061 .- 2769-707X. ; 42:5, s. 427-434
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the association between plasma trans fatty acids (TFAs) and bone mineral density (BMD) and risk of fracture among US adults. Furthermore, we have evaluated the impact of inflammation on this relationship. Methods: Participants (the National Health and Nutrition Examination Survey) with measured data on BMD and TFAs were included. TFAs were measured by gas chromatography–mass spectrometry and BMD was measured using dual-energy x-ray absorptiometry densitometers. Results: Of the 4022 eligible participants, 48.1% were men. The mean age of the population sample was 44.6 years. In the model adjusted for age, sex, race, education, income, physical activity, smoking, fasting blood glucose, systolic and diastolic blood pressure, body mass index, diabetes, and hypertension, across the increasing quartiles (Q) of individual plasma TFAs, BMD decreased for most of the sites measure: for example, Q1 vs. Q4 1.04 vs. 0.095 g/cm2 for palmitelaidic acid and 1.11 vs. 0.099 g/cm2 for elaidic acid (all p < 0.001). In models using the same adjustment, linear regression displayed a significant negative association between plasma TFAs and BMD for most of the sites measured (all p < 0.001). Moderation analysis revealed that inflammation [assessed as a serum C-reactive protein (CRP)] was not significantly implicated in the relationship between BMD and TFAs. There was no significant difference in percentage of fractures (hip, spine, wrist) observed across quartiles of plasma TFAs (all p > 0.125). Conclusions: Our findings highlight, for the first time, the potentially detrimental impact of plasma TFAs on bone health that does not appear to be moderated through inflammation.
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| 3. |
- Mazidi, Mohsen, 1989, et al.
(författare)
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The Link between Serum 25-Hydroxyvitamin D, Inflammation and Glucose/ Insulin Homeostasis Is Mediated by Adiposity Factors in American Adults
- 2023
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Ingår i: British Journal of Nutrition. - 0007-1145 .- 1475-2662. ; 130:3, s. 423-432
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Tidskriftsartikel (refereegranskat)abstract
- Prior studies have suggested a significant association between 25-hydroxyvitamin D (25(OH)D) concentrations with markers of inflammation and glucose and insulin homeostasis. However, it is unclear whether these associations are confounded or mediated by adiposity. We used an established mediation analysis to investigate the role of adiposity in the relation between serum 25(OH)D with markers of inflammation and glucose and insulin metabolism. We used data from National Health and Nutrition Examination Survey (2005-2010), to evaluate the associations between serum 25(OH)D and markers of insulin resistance or inflammation, and whether these associations are mediated by adiposity factors including body mass index (BMI, marker of body adiposity), waist circumference (WC, marker of central adiposity), anthropometrically predicted visceral adipose tissue (apVAT), and Visceral Adiposity Index (VAI). Analysis of co-variance and conceptual causal mediation analysis were conducted taking into consideration the survey design and sample weights. A total of 16,621 individuals were included; 8607 (48.3%) participants were men and the mean age of the population was 47.1 years. Mean 25(OH)D serum concentration for the overall population was 57.9±0.1 nmol/L with minimal differences between men and women (57.5±0.2 nmol/L and 58.2±0.2 nmol/L, respectively). After adjustment for age, sex, season and race/ethnicity, mean levels of C-reactive protein (CRP), apolipoprotein B (apo-B), fasting blood glucose (FBG), insulin, homeostatic model assessment of IR (HOMA-IR) and β cell function (HOMA-β), haemoglobin A1c (HbA1c), and 2-h glucose were lower for the top quartile of serum 25(OH)D (all p<0.001). Body mass index (BMI) was found to have significant mediation effects (to varied extent) on the associations between serum 25(OH)D and CRP, apo-B, fasting glucose, insulin, HOMA-IR, HOMA-B and HbA1c (all p<0.05). Both waist circumference and apVAT were also found to partly mediate the associations between serum 25(OH)D with CRP, FBG, HbA1c, triglycerides and HDL-cholesterol (all P < 0.05). VAI was found to have mediation effects on CRP only (p<0.001). Using a mediation model, our findings suggest that the relationship between serum 25(OH)D, insulin resistance and inflammation, may be in part mediated by adiposity. These findings support the importance of optimizing 25(OH)D status in conditions with abnormal adiposity (i.e., obesity) and treatments for the prevention of cardio-metabolic diseases affecting adipose tissue metabolism (i.e., weight loss).
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