The association between gut microbiota and resting metabolic rate in overweight/obese women: a case-control study.

Purpose: When examining the underlying processes of obesity, evaluation of gut flora and energy homeostasis can be crucial since disruption of the normal gut microbiota community and energy imbalances are significant factors in the development of obesity. Therefore, this study aimed to compare the relative abundance of important obesity modulator gut microbiota (including Firmicutes, Bacteroidetes, Bifidobactrium spp., Lactobacillus spp., Bacteroides fragilis, Faecalibacterium prausnitzii, Akkermansia muciniphila, and Escherichia coli) in fecal samples of normometabilic and hypometabolic overweight/obese individuals. Methods: This matched case-control study conducted on 36 healthy women aged 18-50 years old. An indirect calorimeter and impedance body analyzer were used to assess resting metabolic rate (RMR) and body composition, respectively. Dietary intake and physical activity were assessed using questionnaires. To determine the abundance of the abovementioned gut microbiota, quantitative polymerase chain reaction (qPCR) method was performed. Moreover, ELISA kits were used to assess leptin, ghrelin, and insulin hormones. Results: The results highlighted higher load of Firmicutes (p = 0.02), F. prausnitzii (p < 0.001), and B. fragilis (p = 0.02) in the normometabolic individuals compared to the hypometabolic ones. Besides, the positive correlation between the abundance of Firmicutes (ß = 7.76 × 10-1, p = 0.01), F. prausnitzii (ß = 1.29 × 10-5, p = 0.01), and B. fragilis (ß = 4.13 × 10-6, p = 0.04) with the RMR have been shown. Whereas the abundance of Bacteroidetes, A. muciniphila, Lactobacillus spp., Bifidobactrium spp., and E. coli showed no significant difference (p > 0.05) and no significant correlation with the RMR except Lactobacillus spp. (ß = 1.73 × 10-4, p = 0.01). Conclusion: It seems that gut microbiota can be a potential target for refining host energy homeostasis and treating obesity and its consequences.

The association of dietary approaches to stop hypertension (DASH) with the odds of diabetic nephropathy and metabolic markers in women: a case-control study.

OBJECTIVES: Epidemiologic studies have reported that diet is associated with diabetes and its complications through different pathways. We sought to examine the associations between the Dietary Approaches to Stop Hypertension (DASH) diet and the odds of diabetic nephropathy (DN) developing in Iranian women with existing type 2 diabetes. METHODS: In this case-control study, 105 women with DN and 105 controls, matched for age and diabetes duration, were selected from the Kowsar Diabetes Clinic in Semnan, Iran. DASH, estimated using dietary intake, was assessed using a validated and reliable food frequency questionnaire with 147 items. Anthropometric measurements were assessed for all subjects. Logistic regression was performed to examine the association between DASH and the odds of developing DN. RESULTS: After controlling for potential confounders, subjects in the highest intake of DASH diet adherence have 84% lower odds of DN, compared to those with the lowest intake (OR = 0.16, 95% CI = 0.07-0.34, P < 0.001). Among DASH diet subcategories, intakes of vegetables (80%), fruits (88%), nuts and legumes (87%), and low-fat dairy (73%) decreased the risk of DN after adjustment for confounders (P < 0.001). CONCLUSIONS: This study showed that the DASH diet is associated with lower odds of DN development in women with type 2 diabetes.

The association between a low-carbohydrate diet score and the risk of diabetic nephropathy in women: A case-control study.

OBJECTIVES: Because evidence linking carbohydrate consumption to diabetic nephropathy (DN) is scarce, and the association between a low-carbohydrate diet (LCD) and DN has not been investigated, we sought to investigate whether a higher LCD score is associated with DN among women. METHODS: In a case-control study, 105 women with type 2 diabetes mellitus and DN and 105 controls with type 2 diabetes mellitus and without DN who attended Kowsar Diabetes Clinic in Semnan, Iran, were matched for age and diabetes duration. The data related to anthropometric and biochemical measures were collected and a food frequency questionnaire with 147 items was used to assess dietary intake. Based on the food frequency questionnaire, we calculated an LCD score for each study participant. Multivariate logistic regression was performed to examine the association between an LCD score and the odds of developing DN. RESULTS: The results of the study demonstrated that the LCD score was not significantly associated with DN in the crude model (odds ratio = 0.39; 95% confidence interval, 0.14-1.07; P = 0.06). However, after adjusting for several confounders, subjects in the top quartile of the LCD score were associated with a 71% lower risk of DN (odds ratio [OR] = 0.29; 95% confidence interval, 0.10-0.86; P = 0.02). A significant trend toward decreased urinary albumin excretion was found with an increase in the LCD score (P = 0.005). CONCLUSIONS: A diet low in carbohydrates was inversely associated with risk of DN. Further observational studies, and preferably randomized controlled trials, are needed to confirm the present results.

The association of appetite and hormones (leptin, ghrelin, and Insulin) with resting metabolic rate in overweight/ obese women: a case-control study.

OBJECTIVE: Low resting metabolic rate (RMR), as a risk factor for weight gain and obesity, can be influenced by many factors. Empirical research has confirmed the role of appetite and related hormones in obesity and energy intake. This study aimed to investigate the relationship between appetite and related hormones in overweight or obese Iranian women with normal and hypo RMR. METHODS: This case-control study was conducted on 42 Iranian adult women (21 cases, and 21 controls), aged 18-48 years. An impedance body analyzer was used to obtain the body composition and an indirect calorimeter was used to assess the RMR. The Flint questionnaire was used to assess appetite, dietary intake, and physical activity were assessed by FFQ and IPAQ questionnaires respectively, and ELISA kits were used to assess leptin, ghrelin, and insulin hormones. RESULTS: The results of the study demonstrated a negative association between ghrelin hormone level (ß = -0.34, 95%CI = -61.70,-3.86, P-value = 0.027) and RMR, and a positive association between insulin hormone level (ß = 0.48, 95%CI = 9.38-34.35, P-value = 0.001) and RMR. Also, results of the appetite questionnaire showed that, in general, both appetite (ß = 0.32, 95%CI = -0.10-2.99 P-value = 0.044) and hunger variable (ß = 0.30, 95%CI = 0.04-5.87, P-value = 0.047) have a positive association with RMR. There was no significant association between leptin levels and RMR. CONCLUSION: It is evident that appetite and related hormones have a potential role in promoting a normal RMR.