Higher dietary methyl donor micronutrient consumption is associated with higher muscle strength in adults: a cross-sectional study.

Methyl donor micronutrients might affect muscle strength via DNA methylation. We aimed to evaluate the combined relationship of dietary methyl donor micronutrients containing betaine, choline, methionine, vitamin B12, vitamin B6 and folate on muscle strength. This cross-sectional study was conducted on 267 subjects including 113 men and 154 women. Dietary intake of micronutrients was assessed utilising a validated 168-item semi-quantitative FFQ, and methyl donor micronutrient score (MDMS) was calculated. The muscle strength of the participants was measured using a digital handgrip dynamometer. The association was determined using linear regression analysis. The mean age of participants was 36·8 ± 13·2 years. After taking into account potential confounding variables, there was no significant association between dietary methyl donor micronutrient score (MDMS) and the mean left-hand muscle strength (ß: 0·07, se: 0·05, P = 0·07); however, the changes were significant in the mean right-hand muscle strength (ß: 0·09, se: 0·04, P = 0·03). There was also a significant positive relationship between mean muscle strength and methyl donors' intake after fully adjusting for potential confounders (ß: 0·08, se: 0·04, P = 0·04). In conclusion, our findings revealed that higher dietary methyl donor micronutrient consumption is associated with enhanced muscle strength. As a result, advice on a higher intake of methyl donor-rich foods including grains, nuts, dairy products and seafood might be recommended by dietitians as a general guideline to adhere to. Additional prospective studies are needed to confirm the findings.

Association of low-carbohydrate diet score and carbohydrate quality with visceral adiposity and lipid accumulation product.

The present study examined the association between low-carbohydrate diet (LCD) score, glycemic index (GI), and glycemic load (GL) with visceral fat level (VFL) and lipid accumulation product (LAP). This cross-sectional study was conducted on 270 adults (118 men and 152 women) aged between 18-45 living in Tehran, Iran, between February 2017 and December 2018. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire (FFQ). Body composition were also assessed. We used analyses of covariance and binary logistic regression to explore associations after controlling for age, energy intake (model 1), education, smoking status, physical activity, occupation, marriage and metabolic diseases. There were no significant differences between tertiles of GI, GL and LCD for means of anthropometric measures, LAP and VFL index in men, while women in the highest tertile of GI and GL had significantly higher mean LAP in the crude model (P = 0·02) and model 1(P = 0·04), which disappeared after controlling for other confounders (P = 0·12). Moreover, the OR and CIs for having high LAP and VFL was not associated with dietary GI, GL and LCD in crude and adjusted models. However, chance of high VFL reduced by 65% and 57% among women with high adherence to LCD score (OR = 0·35, 95% CI = 0·16-0·78, P = 0·01) and model 1 (OR = 0·43, 95% CI = 0·18-1, P = 0·05), respectively. However, this significant association disappeared after controlling for other confounders (P = 0·07). Overall, we found carbohydrate quality and LCD score are not associated with LAP and VFL index. However, gender-specific relationship should not be neglect and warrants further investigation.

Association of major dietary patterns with resting metabolic rate and body fatness in middle-aged men and women: Results from a cross-sectional study.

Background: The association of dietary patterns and resting metabolic rate is still unclear. Aim: To study the relationship between the major dietary patterns, resting metabolic rate, and adiposity measures in Iranian adults. Methods: This is a cross-sectional study of 270 adults aged between 18-45 years old who lived in Tehran. Dietary intakes were achieved using food frequency questionnaire. Resting metabolic rate was measured using indirect calorimetry. Anthropometric measures were recorded using body composition analyzer. Results: Three major dietary patterns were identified by factor analysis labeled as healthy pattern (vegetables, fruits, and fruits juices, legumes, poultry, nuts, fish, egg, low fat dairy product, olive, and olive oil), mixed pattern (non-refined cereals, vegetables, vegetable oils, mayonnaise, high fat dairy product and, pickles), Western pattern (refined cereals, red or processed meat, soft drinks, sweets and desserts, Tea and coffee, salty snacks and French fries). After adjusting for covariates higher score of the Western dietary pattern was associated with lower resting metabolic rate (p = 0.023). There was significant decreasing difference in means for fat free mass across tertiles of mixed pattern when the first tertile was compared to the third tertile (p = 0.046). Higher adherence to healthy pattern was associated with lower body weight (p = 0.034), body mass index (p = 0.021), and higher resting metabolic rate (p = 0.033). Conclusions: Higher adherence to the Western dietary pattern was associated with a lower amount of resting metabolic rate. Also higher adherence to the healthy dietary pattern was associated with higher resting metabolic rate and lower body weight and body mass index. Further studies are required to examine the causal relationship between dietary patterns and resting metabolic rate.

Cardiorespiratory fitness is positively associated with both healthy and western dietary pattern in Iranian middle-aged.

Background: The association between dietary patterns and cardiorespiratory fitness (CRF) is not well established. Objective: We sought to investigate association between a posteriori dietary pattern and CRF in middle-aged adults. Design: Adults (n = 276), aged 20-74 years, who were residents of Tehran, Iran were recruited. Diet was assessed by using a validated 168-item semi-quantitative food frequency questionnaire. Principal component analysis was used to derive dietary patterns. Socio-economic status, anthropometric measures, body composition, and blood pressure were recorded. CRF was assessed by using a graded exercise treadmill test. Analysis of variance and linear regression models were used to discern the association between dietary patterns and CRF. Results: Higher scores of the healthy dietary pattern had no association with VO2max (p = 0.13). After controlling for potential confounders, VO2max was positively associated across tertiles of healthy dietary patterns (p < 0.001). Higher adherence to the "mixed" dietary pattern was inversely related to VO2max (p < 0.01). After adjusting for confounders, the significant association disappeared (p = 0.14). Higher scores of the "Western" dietary pattern was not associated with VO2max (p = 0.06). However, after controlling for potential confounders, VO2max was positively associated with the "Western" dietary pattern (p = 0.01). A positive linear association between the "healthy" dietary pattern and CRF for the total sample (R2 = 0.02; p < 0.01) were presented. Conclusions: Overall, our findings suggest that higher adherence to a "healthy" and "Western" dietary pattern was positively associated with CRF. However, further studies are required to examine and clarify the causal relationship between dietary patterns and CRF.

The association between dietary inflammatory index, muscle strength, muscle endurance, and body composition in Iranian adults.

PURPOSE: Dietary factors may modulate inflammation status which contributed to the various chronic diseases like sarcopenia. Therefore, we aimed to examine the association of dietary inflammatory index (DII) and muscle strength (MS), muscle endurance (ME), and body composition. METHODS: This cross-sectional study was conducted in 270 adults living in Tehran, Iran. The DII was calculated using a validated food frequency questionnaire. Body composition (fat-free mass (FFM), fat mass (FM), percent body fat (PBF), skeletal muscle mass (SMM)) was measured using body composition analyzer. Anthropometric measures (weight, body mass index (BMI), waist circumference (WC)), were done. MS was measured by a digital handgrip dynamometer in both right (MSR) and left (MSL) hand. Mean of MSR and MSL was considered as MS. RESULTS: A significant decrease was found for MS (p < 0.01) and MSR (p < 0.01) across tertiles of DII. Participants who had greater scores of DII also had lower MER (p < 0.01), even after adjustment for confounding factors (age, sex, education status, income, smoking, physical activity, body mass index and energy intake) (p < 0.02). Adherence to DII was significantly related to MSL (p < 0.01), ME (p < 0.01), and ME of the MEL (p = 0.02) in the crude model, which was disappeared after controlling for covariates. Those in the third compared to the lowest tertile of DII, had no significant difference in mean of FFM (p < 0.001), SMM (p < 0.001), and WC (p < 0.001). CONCLUSIONS: Higher DII scores were associated with less muscle strength and endurance among Iranian adults. Further studies are needed to confirm the veracity of our results. LEVEL OF EVIDENCE: Descriptive cross-sectional study, Level V.

A negative association of dietary advanced glycation end products with obesity and body composition in Iranian adults.

Obesity caused by excessive deposited fat is generally classified as BMI ≥ 30 kg/m2. Research regarding the association between dietary advanced glycation end products (dAGE) and obesity is limited. The aim of the present study was to investigate the association between dAGE and obesity and body composition in Iranian adults. This cross-sectional study included 265 adults aged 18-75 years from Tehran, Iran. dAGE were estimated using a validated semi-quantitative FFQ, according to the published food carboxymethyl lysine-AGE database for 549 routinely consumed food items for the Northeastern American multiethnic urban population, and were reported by dividing total energy intake. Dietary intake, sociodemographic data and physical activity status were collected using validated questionnaires, and anthropometric characteristics were measured. Body composition was assessed by bioelectrical impedance analysis, and obesity was defined based on WHO guidelines. The intake of fat and meat was significantly increased in higher tertiles, compared with the first tertile of dAGE (P < 0·001). No association between dAGE and body composition measures and obesity was observed; however, there was a significant negative association between dAGE and BMI (BMI; P = 0·01), waist circumference (P = 0·01), waist:hip ratio (P = 0·03), fat-free mass (P = 0·02) and muscle mass index (P = 0·01) in non-linear models. In conclusion, higher consumption of dAGE was associated with increased intake of fat and meat and was negatively related to changes in body composition measurements. Therefore, dAGE may connect obesity to diet by energy imbalance.

Lack of a relationship between vitamin D status and resting metabolic rate in Iranian adults.

OBJECTIVES: Studies suggest a positive relationship between 25-hydroxy vitamin D (25(OH)D)) and resting metabolic rate (RMR). We aimed to determine whether this relationship was also true of populations with very low vitamin D status. METHODS: Fat mass (FM) and fat free mass (FFM) were determined from multifrequency bioimpedance analysis (InBody 720, Korea). RMR was based on indirect calorimetry (Cortex Metalyser 3B, Germany). Fasting blood measurements of 25(OH)D concentration, glucose and triglycerides were measured. Data were analyzed separately on men and women by tertile of vitamin D status and multiple linear regression analysis. RESULTS: Two hundred and sixty-three subjects (115 males; 148 females) with a mean age of 37 years and mean %body fat of 30.5% were studied. In women but not men, age, body weight, waist circumference, FM, and FFM increased significantly across tertiles of 25(OH)D. However, there was no difference in unadjusted or adjusted RMR across tertiles of 25OHD in both women and men. Stepwise forward regression analysis showed that age and FFM in men, age and FM in women but not by 25(OH)D, were determinants of RMR. In addition, RMR adjusted for age, sex, FM, FFM and triglyceride-glucose index did not relate to 25(OH)D when linear (r = 0, P = .98), quadratic (r = 0.008, P = .34), or cubic (r = 0.010, P = .43) relationships were tested. CONCLUSIONS: Residual variation in RMR did not relate to vitamin D status in a group of Iranian adults with very low vitamin D status. Future studies could examine whether such a relationship holds true, after the normalization of vitamin D status.

The interaction of aging with serum 25(OH)D and 1,25(OH)2 D status on muscle strength.

BACKGROUND: To investigate the combination relationship of age with serum 25-hydroxyvitamin D (25(OH) D) and 1,25-(OH)2D3 levels on muscle strength. METHODS: We performed a cross-sectional study on 270 subjects containing 115 men and 155 women. Serum concentration of 25(OH) D and 1,25-(OH)2D3 were assessed. Hand grip strength (HGS) was measured using a digital dynamometer. RESULTS: There was no significant difference in mean of HGS among tertiles of 25(OH)D (P = .350) and 1,25(OH)2 D (P = .467) before and after controlling for potential confounding factors. A significant difference in HGS was found between age categories in both crude (P < .001) and adjusted models (P = .018), where mean grip strength increased in the three first age categories, but decreased in the last group (48-69 years old). There was also a significant interaction between age and 25(OH) D (P = .049) and 1,25-(OH)2D3 (P = .047) on HGS, in which the combination effect increased the mean of muscle strength up to middle age after adjusting for confounders. CONCLUSIONS: Serum 25(OH)D and 1,25(OH)2 D were not related to muscle strength. However, age, and combination of age with both 25(OH)D and 1,25(OH)2 D, significantly resulted in improving in muscle strength up to middle age.

The lack of association between dietary antioxidant quality score with handgrip strength and handgrip endurance amongst Tehranian adults: A cross-sectional study from a Middle East country.

OBJECTIVE: The association between dietary antioxidant quality score (DAQS) and handgrip strength (HS) and handgrip endurance (HE) is still unclear. We aimed to investigate whether adherence to dietary antioxidant quality score (DAQS) is associated with handgrip strength (HS) and handgrip endurance (HE) amongst adults in Tehran. METHODS: This cross-sectional study was conducted on 270 (43.7% males, mean age 37 years and 56.3% females, mean age 35 years) apparently healthy adult subjects (53.2% were married) selected from different parts of Tehran, Iran. Dietary intake was assessed using a 168-item validated food frequency questionnaire. DAQS was calculated using antioxidant-nutrient intake. Body composition was measured using a body composition analyser. Handgrip strength and endurance were measured by a digital handgrip dynamometer. Relative muscle strength was expressed as the ratio of handgrip strength by body mass index (BMI). RESULTS: The results showed that DAQs had no significant association with HS (P = .67, adjusted R2  = .60) and HE (P = .19, adjusted R2  = .08) after adjusting for potential confounders. However, a significant positive association was found between selenium intake and HE even after adjusting for potential confounders (P = .01, adjusted R2  = .10). After controlling for potential confounders no differences in the mean of HS (P = .29) and also HE (P = .61) amongst tertiles of DAQS was found. Positive linear association was found between vitamin C (P = .02, adjusted R2  = .53) and vitamin E (P = .03, adjusted R2  = .55) intake with relative muscle strength. CONCLUSION: Our results revealed that no significant association between DAQS and HE and HS. It was found that more intake of selenium was positively linked to HE. Dietary intake of vitamin C and vitamin E are associated with higher relative muscle strength. It is evident that more prospective studies are needed to confirm the veracity of our results.

Association between the empirical dietary inflammatory index and cardiorespiratory fitness in Tehranian adults in 2017-2018.

Background: Inflammatory-related chronic diseases are increasing in Iran with high consumption of a diet containing pro-inflammatory potential and a sedentary lifestyle. The empirical dietary inflammatory index (EDII) was developed as a tool to assess dietary effects on systemic inflammation. We examined the hypothesis that specific dietary patterns reflecting systemic inflammation are associated with cardiorespiratory fitness (CRF) in Tehranian adults. Methods: This cross-sectional study was carried out on 270 adults who are residents of Tehran. Dietary intake was assessed using a 168-item valid and reliable food frequency questionnaire. The EDII score was developed according to participant dietary intakes of 21-item pre-defined food groups. CRF was assessed by using a graded exercise treadmill test. Anthropometric measurements were assessed using standard methods. To discover the association between CRF and EDII, we used multivariable logistic regression analysis. Results: Those who were in the third tertile of the EDII had 57% lower odds of having better VO2Max (ml/kg/min) than those in the first tertile (OR: 0.43; 95% CI: 0.16, 1.12, p = 0.01). There were no significant differences between tertiles of the EDII score in terms of VO2 (L·min) and VO2 (LBM) before and after adjusting for confounders. There was a significant decrease in VO2Max (ml/kg/min) across tertiles of the EDII after controlling for covariates (p-value = 0.04). There was a significant inverse association between the EDII score and VO2Max (ml/kg/min) (ß = -0.35, p = 0.001). Conclusions: Our finding demonstrated that a higher EDII might be associated with lower CRF in Tehranian adults. Prospective studies are needed to shed light on the causal link between the EDII and CRF.

Cross sectional determinants of VO2 max in free living Iranians: Potential role of metabolic syndrome components and vitamin D status.

BACKGROUND AND AIMS: The purpose of the study was to evaluate the determinants of cardiorespiratory fitness (CRF) in Iranian adults and the potential contribution of vitamin D status. METHODS: In this cross-sectional study 264 cases (116 men and 147 women aged 18-70 years old were participated. Maximal oxygen consumption (VO2 max) was measured by the Bruce protocol utilizing treadmill exercise testing. Anthropometric data, body composition and fasting blood glucose and lipid concentrations were measured. Serum levels of 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) were assessed using enzyme-linked immunosorbent assay. Stepwise linear regression analysis was applied to determine significant predictors of VO2 peak. We tested non-linear (quadratic and cubic terms) versus linear association of adjusted (for determinants) VO2 max and vitamin D levels. RESULTS: Multiple regression results showed that fat free mass, HDL-C and physical activity, waist circumference, age and sex were determinants of VO2 peak. All of these explained the 65.3% of VO2 peak. There was a non-linear cubic association (R2 = 0.03, p = 0.046) between serum 25(OH)D and adjusted VO2 peak in which 25(OH)D in people with a high 25(OH)D levels (>60 nmol/L), had better fitness and those with serum 25(OH) less than 20 nmol/L. We found no linear and non-linear associations between serum 1,25(OH)2 D and adjusted VO2 max. CONCLUSIONS: Our results showed that waist circumference and HDL-C, as components of metabolic syndrome, contribute ∼2% to the variance in VO2 max. Moreover, high concentrations of 25(OH)D but not 1,25(OH)2 D may make additional contributions to CRF.

The Association of Dietary Energy Density and Body Composition Components in a Sample of Iranian Adults.

Background: We aimed to investigate the association between the energy density (ED) of diet and body composition components in Iranian adults. Methods: We conducted a cross-sectional study on 267 adults in Tehran. We obtained ED (kcal/g) using the two most common methods: ED1, ED from foods only with the exclusion of all beverages and ED2, from foods and all beverages. Body composition was measured using a multifrequency bio-impedance analysis. To find a strong association, we used both the linear and binary regression analysis in the three adjusted models. Results: The mean of ED1 and ED2 was 1.34 ± 0.23 and 0.89 ± 0.20 kcal/g, respectively. Increasing the ED of diet in both methods was associated with a high intake of dietary fat, of saturated fatty acid (SFA), of monounsaturated fatty acid (MUFA), of polyunsaturated fatty acid (PUFA), of oleic and linoleic acids, accompanied by a low intake of fruits, vegetables, and some vitamins and minerals. There was a significant positive relationship between fat-free mass index (FFMI) and ED1 (ß = 4.44, p = 0.02). However, we found no significant association between the consumption of ED1 and fat mass index (FMI) (0.28; 95% CI 0.08, 0.98; p = 0.07), and abdominal obesity (0.91; 95% CI 0.43, 1.94; p = 0.82). Also, ED2 had no association with FMI (0.86; 95% CI 0.26, 2.80; p = 0.81) and abdominal obesity (0.78; 95% CI 0.35, 1.72; p = 0.54). No significant associations were found between ED and other anthropometric indices and body composition components after considering the confounders. Conclusion: This study supports the positive association between ED and poor dietary quality. However, our findings did not show significant associations of dietary energy density (DED) with anthropometric indices and body composition components. Further well-designed studies are required to investigate the exact link between DED and body composition.

The low-carbohydrate-diet score is associated with resting metabolic rate: an epidemiologic study among Iranian adults.

PURPOSE: Low-carbohydrate diet (LCD) has been used for weight loss and preventing obesity, but the association of adherence to LCD and resting metabolic rate (RMR) has not been investigated. This study aimed to investigate the association between the low-carbohydrate-diet score (LCDS) and RMR among Iranian adults. METHODS: This cross-sectional study was conducted on 270 Iranian adults 18-70 y of age. To assess dietary intakes, participants completed a validated food frequency questionnaire. The LCDS was calculated based on carbohydrate, protein and fat intake, expressed as a percentage of energy. The higher score indicates the lower carbohydrate and the higher protein and fat intake. RMR was measured by indirect calorimetry after an overnight fast. RESULTS: Multivariate-adjusted means showed that RMR significantly increased across tertiles (p = 0.041). However, there were no significant differences in the mean of fat mass (FM) and fat-free mass (FFM) across tertiles of LCDS (p = 0.986 and p = 0.621, respectively). Also LCDS and RMR (r = 0.14, p = 0.021) were found to be correlated, but LCDS and FFM (r = 0.06, p = 0.323), FM (r = -0.05, p = 0.412), had no statistically significant correlation. RMR had a significant positive association with LCDs in the crude model (ß = 18.81, 95% CI: 2.55, 35.07, P = 0.024). Moreover, after controlling for covariates this association changed to non-significant (ß = -0.14, 95% CI: -7.05, 19.25, P = 0.03). CONCLUSION: Adherence to diets lower in carbohydrates and higher in fat and protein were associated with higher RMR. Further studies with a larger sample size are needed to confirm these findings.

Associations of physical activity with cardiorespiratory fitness, muscle strength, and body composition.

INTRODUCTION: Most studies have indicated the association between physical activity level (PAL) and physical fitness indices in children and adolescents. This study aimed to investigate the association of PAL with cardiorespiratory fitness, muscle strength, and body composition in healthy Iranian adults. MATERIAL AND METHODS: This cross-sectional study was carried out on 120 males and 152 females aged 18-70 years. The participants underwent physical fitness measurements including grip strength, maximal oxygen consumption, and body composition. The PAL was objectively assessed using the International Physical Activity Questionnaire (IPAQ). RESULTS: We observed a significant association between PAL and body composition measurements (p < 0.05). Controlling for covariates did not change the results except for body mass index and waist circumference. All cardiorespiratory fitness and muscle strength indexes were positively associated with PAL (p < 0.001 and p = 0.001, respectively). However, these associations were disappeared after adjustment for age, gender, and BMI. CONCLUSIONS: Improved body composition profile and function of the muscular and cardiovascular system were associated with higher PA. Further longitudinal studies are required to understand the causal direction of the relationship.

Association of major dietary patterns with muscle strength and muscle mass index in middle-aged men and women: Results from a cross-sectional study.

BACKGROUND: Dietary patterns may affect muscle mass, strength, and function; hence, we evaluated the association of major dietary patterns in relation to muscle mass index (MMI) and muscle strength in middle-aged adults. We hypothesized that unhealthy dietary patterns are associated with reduced muscle mass and muscle strength. SUBJECTS: and methods: The present cross-sectional study recruited 270 adults (118 males and 152 females) aged between 18 and 75 years' old. Socio-demographic data, body composition and muscle strength were determined. MMI was calculated by total fat free mass (FFM) (kg)/height2 (m). Dietary intake was assessed using a 168-item validated food frequency questionnaire. Factor analysis was conducted, and as a result, 3 factors were extracted. These factors were labeled as healthy, mixed and western dietary patterns. RESULTS: After control for potential confounders, there were a positive trend between tertiles of "healthy dietary pattern" and muscle strength (p = 0.03). Moreover, we found that those who were in the third tertile of "mixed dietary pattern" compared to those at the first tertile had no significant relationship with muscle strength (p = 0.42) and MMI (p = 0.36) even after controlling for potential confounders. In contrast, the adherence to the "Western dietary pattern" was associated with reduced MMI (p = 0.02). CONCLUSION: Adherence to healthy dietary pattern might be associated with better muscle strength and greater adherence to Western pattern appears to reduce MMI.

The association of plant-based dietary patterns with visceral adiposity, lipid accumulation product, and triglyceride-glucose index in Iranian adults.

BACKGROUND: We sought to investigate whether adherence to a more plant-based, and less animal-based, diet is associated with visceral adiposity, lipid accumulation product (LAP), and triglyceride-glucose index (TyG) in Iranian adults. METHODS: This cross-sectional study was conducted on 270 adults aged between 18-75 years old. We created three plant-based diets. including an overall plant-based diet index (PDI), hPDI, and uPDI based on tertiles regarding the intake of animal- or plant-based food items obtained from a semi quantitative food-frequency questionnaire. RESULTS: Higher hPDI was significantly associated with lower body mass index (BMI) (P-value = 0.01), lower waist circumference (P-value<0.001), and lower waist-hip ratio (P-value<0.001). A significant increase was found for high density lipoproteins (HDL) (P-trend <0.001) with a significant decrease for LAP (P-value = 0.03) in those with higher adherence to hPDI. Moreover, greater adherence to PDI was associated with a significant increase in diastolic blood pressure (DBP) (p-value = 0.01) and fat free mass (FFM) (p-value = 0.01). There were no significant associations between PDIs and TyG and VFA. CONCLUSION: We found that a higher hPDI score was significantly associated with better anthropometric measurements. A significant increase was found for HDL and a significant decrease was found for LAP on hPDI. However, a higher PDI score was significantly associated with higher DBP and higher FFM.

The association between dietary acid load and muscle strength among Iranian adults.

OBJECTIVE: There is limited evidence regarding the association between dietary acid load and muscle strength. Thus, in this study, we investigated the association between dietary acid-base load indices and muscle strength among Iranian adults. RESULTS: This cross-sectional study was conducted on 270 Iranian adults, aged 18-70 year. Dietary acid load indexes, were calculated by using a validated 168-item semi-quantitative food frequency questionnaire (FFQ). Muscle strength was measured by a digital handgrip dynamometer. There was a significant increase in mean muscle strength of left-hand (MSL), muscle strength of right-hand (MSR) and the mean of the MSL and MSR (MMS) across tertiles of Potential Renal Acid Load (PRAL), Net Endogenous Acid Production (NEAP), and Dietary Acid Load (DAL). Significant linear relationships between PRAL and; MSL (ß = 0.24, p < 0.001), MSR (ß = 0.23, p < 0.001) and MMS (ß = 0.24, p < 0.001), between NEAP and MSL (ß = 0.21, p < 0.001), MSR (ß = 0.19, p = 0.002), and MMS (ß = 0.20, p = 0.001) and between DAL and MSL (ß = 0.25, p < 0.001), MSR (ß = 0.23, p < 0.001) and MMS (ß = 0.24, p < 0.001), were attenuated after controlling for potential confounders. However, the nonlinear relationship between dietary acid load indicators and muscle strength were significant (p < 0.001 for all).

Association of Dietary Patterns with Visceral Adiposity, Lipid Accumulation Product, and Triglyceride-Glucose Index in Iranian Adults.

In the present study, we sought to examine the association between dietary patterns (DPs) and visceral adiposity, lipid accumulation product (LAP), and triglyceride-glucose index. This cross-sectional study was conducted on adults aged between 18-45 years old who lived in Tehran, Iran, between February 2017 and December 2018 (n = 270). DPs were derived using principal component analysis. We used analysis of variance to examine differences in continues variables across tertiles of major DPs. Subsequently, for the modeling of these relationships, and also considering the possible effect of the confounding factors, multivariate regression was used. Three DPs were identified: healthy pattern, mixed pattern, and western pattern, respectively. Compared with individuals in the lowest category of mixed pattern, those in the highest category had lower fasting blood sugar (96.26 ± 11.57 vs. 101 ± 28.66, p = 0.01). A significant association was found between healthy pattern, after adjustment for potential confounders, and odds of LAP; such that individuals in the top category of healthy pattern score were 71% less likely to have a high LAP compared with those in the lowest category (odds ratio, 0.29; 95% confidence interval, 0.10-0.81). We found that adherence to a healthy DP was associated with decreased LAP. To confirm the veracity of these findings, more studies should be conducted.