Badri, N.W., S.W. Flatt, H.S. Barkai, B. Pakiz, D.D. Heath, C.L. Rock, 2018. Insulin resistance improves more in women than in men in association with a weight loss intervention. J Obes Weight Loss Ther. 8(1). pii: 365. doi: 10.4172/2165-7904.1000365.
Background: Fasting glucose and homeostatic model assessment-insulin resistance (HOMA-IR) are important measures of the risk for metabolic syndrome and diabetes. Weight loss interventions are considered part of the first line of therapy for those who develop disease states associated with insulin resistance, such as pre-diabetes, diabetes, or metabolic syndrome. Sex differences in insulin resistance have been extensively reported, but sex differences in the ability to improve insulin sensitivity are not well-established. This study sought to identify factors that predict change in HOMA-IR in response to weight loss. Methods: Non-diabetic subjects who were overweight/obese (n=100) were randomly assigned to a walnut-enriched reduced-energy diet or a standard reduced-energy-density diet in a 6-month weight loss intervention. There were no significant differences in weight change, glucose, insulin, or HOMA-IR between the two diet groups. These subjects were combined into a single cohort and analyzed with multivariate analysis. Results: The combined groups lost an average of 8.7 kg (p<0.0001), decreased serum glucose by an average 0.2 mmol/L (p<0.001), and decreased HOMA-IR by an average of 1.4 (p<0.0001). Change in HOMA-IR (R2=0.69) was positively associated with weight change (p<0.0001) and male sex (p<0.01), and negatively associated with baseline HOMA-IR (p<0.0001). Conclusion: Findings from this study suggest that men may have a more difficult time improving insulin sensitivity as compared with women with an equivalent weight loss and baseline HOMA-IR. One hypothesis to explain the differences across sexes may be due to sex differences in visceral adipose fat (VAT). This may mean that insulin resistant men require more aggressive intervention than women to prevent progression to metabolic syndrome or diabetes.
Arab, L., S.K. Dhaliwal, C.J. Martin, A.D. Larios, N.J. Jackson, D. Elashoff , 2018. Association between walnut consumption and diabetes risk in NHANES. Diabetes Metab Res Rev. Oct; 34(7):e3031. doi: 10.1002/dmrr.3031. Epub 2018 Jul 11.
BACKGROUND: Dietary interventions and cohort studies relating tree nut consumption to blood glucose levels suggest a possible effect of walnuts. OBJECTIVE: To examine the associations between walnut consumption and diabetes risk using data from the National Health and Nutrition Examination Survey (NHANES). METHODS: NHANES survey data on adults conducting 24-hour dietary recall was pooled across the years 1999 through 2014. Diabetes status or risk was based on self-report, medication use, fasting plasma (FPG) glucose levels and hemoglobin A1c (HbA1c) levels. Individuals were characterized based on reported consumption of walnuts, mixed-nuts, or no nuts. RESULTS: After adjustment for covariates, walnut consumers showed lower risk for diabetes compared to non-nut consumers based on self-report (odds ratio of 0.47 95% confidence interval 0.31-0.72) as well as fasting blood glucose (RRR 0.32 CI 0.17-0.58) and HbA1c (RRR 0.51 CI 0.27-0.99). For each standard deviation of increase in walnut intake, prevalence of diabetes dropped 47%. The gender by walnut interaction suggests the effect may be more potent among women than men (dose response p=0.061). CONCLUSIONS: Both among individuals with known diabetes and those diagnosed based on elevated diabetes blood markers, the prevalence of individuals with diabetes was significantly lower among the walnut consumers. A possible gender specific effect invites further attention.
Gulati, S., A. Misra, R.M. Pandey, 2017. Effect of almond supplementation on glycemia and cardiovascular risk factors in Asian Indians in north India with type 2 diabetes mellitus: A 24-week study. Metabolic Syndrome and Related Disorders. doi:10.1089/met.2016.0066.
Background: Type 2 diabetes (T2D) statistics have reached menacing proportions in India. Appropriate dietary intervention, as part of healthy lifestyle, is imperative to curb further spread of this disease. Objectives: This pre–post intervention study was conducted in New Delhi, India, to investigate the effects of daily consumption of almonds for 24 weeks in T2D subjects, specifically on measures of glycemia and cardiovascular disease (CVD) risk factors. Methods and Study Design: In this study, the 24-week intervention period was preceded by a control diet and exercise run-in period of 3 weeks. Raw almonds (20% of energy intake) were provided to the patients for consumption along with diet and physical activity counseling. Patients were assessed for anthropometry, blood pressure, measures of glycemia (fasting blood glucose, glycosylated hemoglobin), lipids [total cholesterol (TC), triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, lipoprotein(a)], surrogate marker of atherosclerosis (Pulse wave velocity), and marker of inflammation (high sensitivity C-reactive protein [hs-CRP]) at baseline and after the intervention period. Results: Statistically significant improvement in mean values for various parameters post intervention was as follows: waist circumference (P<0.03), waist-to-height ratio (P<0.005), TC (P<0.002), serum triglycerides (P<0.004), low-density lipoprotein cholesterol (P<0.01), glycosylated hemoglobin (P<0.04), and hs-CRP (P<0.01). A trend toward improvement in pulse wave velocity (P<0.06) was also observed. Conclusion: The study findings illustrate that incorporation of almonds in a well-balanced healthy diet leads to multiple beneficial effects on glycemic and CVDs risk factors in Asian Indian patients with T2D.
Njike VY, Yarandi N, Petraro P, Ayettey RG, Treu JA, Katz DL, 2016. Inclusion of walnut in the diets of adults at risk for type 2 diabetes and their dietary pattern changes: a randomized, controlled, cross-over trial. BMJ Open Diabetes Res Care. 4(1):e000293.
Abstract: Background: In our recently published study, including walnuts in the diets of adults with prediabetes led to overall improvement in diet quality. This report adds to those study findings by examining the food groups displaced during walnut inclusion in the diets of those adults with prediabetes. Methods: Randomized, controlled, modified Latin square parallel design with 2 treatment arms. The 112 participants (31 men, 81 women) were randomly assigned to a diet with or without dietary counseling to regulate calorie intake in a 1:1 ratio. Within each treatment arm, participants were further randomized to 1 of 2 sequence permutations to receive a walnut included diet with 56 g (366 kcal) of walnuts per day and a walnut-excluded diet. Participants in the calorie regulated arm received advice from a dietitian to preserve an isocaloric condition while including walnuts. We analyzed the 12 components of the 2010 Healthy Eating Index to examine dietary pattern changes of study participants. Results: Seafood and plant protein foods intake significantly increased with walnut inclusion, compared with their exclusion (2.14±2.06 vs −0.49±2.33; p=0.003). The ingestion of healthful fatty acids also significantly increased with walnut inclusion, compared with their exclusion (1.43±4.53 vs −1.76±4.80; p=0.02). Dairy ingestion increased with walnut inclusion in the calorie-regulated phase, compared with walnut inclusion without calorie regulation (1.06±4.42 vs −2.15±3.64; p=0.02). Conclusions: Our data suggest that walnut inclusion in the diets of adults at risk for diabetes led to an increase in intake of other healthful foods.
