Immunomodulatory Effects of Vitamin D and Prevention of Respiratory Tract Infections and COVID-19.

Little is known about potential protective factors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), referred to as COVID-19. Suboptimal vitamin D status is a risk factor for immune dysfunction, respiratory tract infections (RTIs), and viral infections. Supplementation of vitamin D (2000-4000 IU) has decreased incidence and complications from RTIs, respiratory distress syndrome, and pneumonia and may be beneficial in high-risk populations. Given the possible link between low vitamin D status and RTIs, such as COVID-19, this review examined whether vitamin D supplementation can be supported as a nutritional strategy for reducing risk of infection, complications, and mortality from COVID-19 and found that the relationship between vitamin D and RTIs warrants further exploration.

Biomarker Changes in Response to a 12-Week Supplementation of an Oral Nutritional Supplement Enriched with Protein, Vitamin D and HMB in Malnourished Community Dwelling Older Adults with Sarcopenia.

Malnutrition and sarcopenia commonly overlap and contribute to adverse health outcomes. Previously, chronic supplementation with two oral nutritional supplements (ONS), control (CONS) and experimental ONS enriched with protein, vitamin D and ß-hydroxy ß-methylbutyrate (HMB) (EONS), improved muscle strength and quality in malnourished sarcopenic older adults, with EONS demonstrating early strength benefits at 12 weeks. To understand the underlying biological mechanisms contributing to the observed early strength benefits of EONS, we examined serum biomarker changes in response to 12-week supplementation. Serum samples (EONS (n = 90) and CONS (n = 103)) collected at baseline and 12 weeks were analyzed. Biomarkers (n = 243) were measured using multiplexed immunoassay, commercial immunoassays and ELISAs. Sixty markers were excluded with levels below assay detection limits. Sixteen biomarkers significantly changed in response to both interventions including nutritional and metabolic markers. Thirteen biomarkers significantly changed in response to EONS but not CONS. Increases in immunoglobulins, myoglobin, total protein, vitamin E and magnesium were observed with EONS. Inflammation-related ferritin and osteopontin decreased, while soluble receptors for cytokines increased, suggesting decreased inflammation. Sex hormone-binding globulin associated with sarcopenia also decreased with EONS. Biomarkers reflective of multiple biological systems were impacted by nutritional intervention in sarcopenic older adults. Incremental biomarker changes were observed in response to EONS containing HMB that possibly link to improvements in skeletal muscle health.

Differences in muscle energy metabolism and metabolic flexibility between sarcopenic and nonsarcopenic older adults.

BACKGROUND: Metabolic flexibility is the ability of skeletal muscle to adapt fuel utilization to the demand for fuel sources [carbohydrates (CHO) and fats (FAT)]. The purpose of this study was to explore muscle energy metabolism and metabolic flexibility under various conditions in sarcopenic (S) versus nonsarcopenic (NS) older adults. METHODS: Twenty-two older adults aged 65 years or older were categorized as NS [n = 11; mean ± standard deviation (SD); age = 73.5 ± 6.0 years (males, n = 5; females, n = 6)] or S [n = 11; 81.2 ± 10.5 years (males, n = 6; females, n = 5) based on handgrip strength, body composition and physical performance. Indirect calorimetry was recorded before and after consumption of a high-CHO meal and during aerobic and anaerobic exercise. Respiratory quotient (RQ), CHO and FAT oxidation were assessed. Venous blood samples were collected for glucose and insulin concentrations. RESULTS: At rest, compared with NS, S exhibited a 5-8% higher RQ at 0 (0.72 vs. 0.76) and 120 (0.77 vs. 0.82), 150 (0.76 vs. 0.80), and 180 min (0.74 vs. 0.80) (P = 0.002-0.025); 59-195% higher CHO oxidation at 0, 120, and 180 min (0.0004-0.002 vs. 0.001-0.002 g·min-1 ·kg-1) (P = 0.010-0.047); and 20-31% lower FAT oxidation at 0, 15, and 90-180 min (0.0009-0.0022 vs. 0.0011-0.002 g·min-1 ·kg-1 ) (P = 0.004-0.038). Glucose levels were significantly elevated in S versus NS at 0, 60 and 75 min (144.64-202.78 vs. 107.70-134.20 mg·dL-1 ) but not insulin. During aerobic exercise, RQ was 5% greater (0.90 vs. 0.86) (P = 0.039), and FAT oxidation was 35% lower at 6-8 min (0.003 vs. 0.005 g·min-1 ·kg-1 ) (P = 0.033) in S versus NS. During anaerobic exercise, CHO oxidation was 31% greater in NS versus S at 60-80% time to exhaustion (0.011 vs. 0.007 g·min-1 ·kg-1 ) (P = 0.015). Per cent contribution to energy expenditure was greater in S for CHO but lower for FAT at 0 (CHO: 22% vs. 10%; FAT: 78% vs. 91%) and 120-180 min (CHO: 35-42% vs. 17-25%; FAT: 58-65% vs. 75%-84%) (P = 0.003-0.046) at rest and 6-8 min during aerobic exercise (CHO: 70% vs. 57%; FAT: 30% vs. 45%) (P = 0.046). CONCLUSIONS: The data show differences in skeletal muscle energy metabolism and substrate utilization between S and NS at rest, transitioning from fasted to fed state, and during exercise. Compared with NS, S displayed a diminished ability to adapt fuel utilization in response to feeding and exercise, reflecting metabolic inflexibility. Impaired metabolic flexibility could be a mechanism underlying the losses of strength and physical function accompanying sarcopenia.

Impact of slow versus rapid digesting carbohydrates on substrate oxidation in pre-pubertal children: A randomized crossover trial.

BACKGROUND & AIMS: Consumption of rapid digesting sugars by children are under increased scrutiny because of their contribution to unhealthy weight gain. Previous studies in adults and children have suggested that altering the blend of carbohydrates (CHOs) consumed may cause shifts in substrate utilization. The purpose of this study was to examine the effects of consuming a slow digesting carbohydrate (SDC) and rapid digesting carbohydrate (RDC) on CHO and fat oxidation, glucose, and insulin responses at rest, during exercise, and post-exercise rest in pre-pubescent children. METHODS: A randomized, double-blind, crossover design was used. Nineteen pre-pubescent children (n = 10 boys, n = 9 girls, mean ± standard error, age = 9.84 ± 0.37-yrs) participated. Visits to the laboratory began with a 30-min measurement of resting metabolism followed by consumption of either an RDC or SDC drink. Postprandial resting metabolism was recorded for 60-min, immediately followed by 60-min of submaximal cycling exercise while metabolism was recorded, which was immediately followed by another 60-min recording of post-exercise metabolism. Total CHO and fat oxidation, endogenous and exogenous CHO oxidation, blood glucose, and insulin were assessed. RESULTS: Total CHO oxidation rate (g∙min-1) was greater after the RDC drink at 60 min (p = 0.032). Endogenous CHO oxidation rate (g∙min-1) was greater after the SDC drink at 15 min (p ≤ 0.010). Cumulative endogenous CHO oxidation (g) was greater after the SDC drink at 45 min (p = 0.009). Endogenous CHO oxidation accounted for a greater proportion of substrate oxidation after the first 60-min rest period (p = 0.028), while exogenous CHO oxidation accounted for a greater proportion of substrate oxidation for the RDC at all time points (p ≤ 0.019). CONCLUSIONS: The present study provides novel data suggesting that an SDC promotes greater endogenous substrate utilization in pre-pubertal children, which may have beneficial health impacts on energy intake and carbohydrate regulation/metabolism during growth and development. CLINICAL TRIALS REGISTRY NUMBER: NCT03185884, clinicaltrials.gov.

Endogenous versus exogenous carbohydrate oxidation measured by stable isotopes in pre-pubescent children plus 13C abundances in foods consumed three days prior.

PURPOSE: The purposes of the present study were to (a) examine resting metabolism, substrate utilization, and endogenous versus exogenous carbohydrate (CHO) oxidation before and after 30-g rapidly-digesting carbohydrate (RDC) ingestion using indirect calorimetry and breath test analysis of stable isotope concentrations in pre-pubescent children and (b) report the 13C abundances in foods consumed for three days prior. METHODS: Nineteen children (n = 10 boys, n = 9 girls) at Tanner stage I or II participated (mean age ± 95% CI = 9.84 ± 0.77 y) in this study. Food was administered to the children for three days preceding their scheduled breath tests. Breath tests and indirect calorimetry were performed after an 8-h fast before and 60 min following consumption of a 30-g simple RDC drink consisting of maltodextrin and sucrose. Open circuit spirometry and indirect calorimetry monitored resting metabolism and CHO oxidation. Separate breath samples were taken every 15 min. Samples of all foods and breath samples were analyzed for 13C and 12C abundances with a stable-isotope mass spectrometer. RESULTS: 13C in expired breath samples were -23.81 ± 1.64‰ at baseline and increased every 15 min after consumption of the CHO drink (p < 0.001-0.009). Cumulative total, endogenous, and exogenous CHO utilization increased during the post-prandial period (p < 0.001). Endogenous CHO oxidation was consistently greater than exogenous CHO oxidation (p < 0.001-0.002).Blood glucose was elevated from baseline at 30- and 60-min post-prandial (p < 0.001). Insulin did not change over time (p = 0.184). CONCLUSIONS: The foods provided during the 3-day controlled diet effectively minimized 13C variation prior to metabolic testing. The 13C abundances of foods reported herein should serve as practical recommendations to reduce 13C intake before breath tests. While endogenous CHO oxidation remained greater in proportion to exogenous CHO oxidation, these findings suggest that even a relatively small amount of RDC can increase exogenous CHO oxidation and blood glucose in normal-weight children. To further examine shifts in endogenous versus exogenous CHO utilization, we recommend that future studies take steps to minimize 13C variation before breath tests and examine changes in substrate metabolism at rest and during exercise in normal weight and overweight pre-pubescent children. CLINICAL TRIAL REGISTRATION NUMBER: NCT03185884.

Use of a diabetes-specific nutritional shake to replace a daily breakfast and afternoon snack improves glycemic responses assessed by continuous glucose monitoring in people with type 2 diabetes: a randomized clinical pilot study.

INTRODUCTION: This pilot study evaluated the impact of a diabetes-specific nutritional shake (DSNS) used twice daily by people with type 2 diabetes (T2D) on glycemic response assessed by continuous glucose monitoring (CGM). RESEARCH DESIGN AND METHODS: Adults (n=81) with T2D managed by oral medications were studied in a randomized, open-label, three-group parallel study design. The study was conducted in two phases over 14 days: Baseline (days 1-6), during which study participants consumed their habitual self-selected diets (SSD), followed by the Intervention (days 7-14), during which participants were randomized as follows: (1) SSD group received no study product (n=32); (2) DSNS breakfast/afternoon snack (Bkfst/AS) group consumed one DSNS as a breakfast meal replacement and a second to replace their mid-afternoon snack (n=24); (3) DSNS breakfast/prebed snack (Bkfst/PBS) group consumed one DSNS as a breakfast meal replacement and added a second as a prebed snack (n=25). Glucose was assessed by CGM throughout the study. Additionally, participants were asked about snacking behaviors, cravings, and other questions related to the use of DSNS as meal replacements and snacks. RESULTS: All groups reduced their postprandial glycemic response (positive area under the curve (pAUC, mg/min*dL-1)) and adjusted peak value (mg/dL) when compared with the baseline phase. Participants consuming DSNS in place of their usual breakfast showed greater reductions in pAUC compared with the SSD group (p=0.008) for the DSNS Bkfst/AS group with a trend (p=0.069) for the DSNS Bkfst/PBS group. Adjusted peak value showed greater reductions in both DSNS groups as compared with the SSD group (p=0.002 for DSNS Bkfst/AS and p=0.010 for DSNS Bkfst/PBS). Nocturnal glucose variability was significantly decreased during the intervention phase compared with baseline phase in the DSNS Bkfst/AS group (p=0.020), with no significant differences between groups. After intervention, the DSNS Bkfst/AS group had a significantly lower percentage of participants (17%) reporting cravings for starchy meals/sides compared with before the study (33%) (p=0.046). This group also reported a significant increase in confidence in choosing foods to control their diabetes (from 58.3% to 91.7%, preintervention vs postintervention, respectively, p=0.005). CONCLUSIONS: Use of DSNS to replace breakfast and as an afternoon snack improves both glycemic control and behavioral factors related to dietary management of diabetes. TRAIL REGISTRATION NUMBER: NCT04230889.

The Role of Dietary Carbohydrates in Gestational Diabetes.

Gestational diabetes (GDM) is hyperglycemia that is recognized for the first time during pregnancy. GDM is associated with a wide range of short- and long-term adverse health consequences for both mother and offspring. It is a complex disease with a multifactorial etiology, with disturbances in glucose, lipid, inflammation and gut microbiota. Consequently, its management is complex, requiring patients to self-manage their diet, lifestyle and self-care behaviors in combination with use of insulin. In addition to nutritional recommendations for all pregnant women, special attention to dietary carbohydrate (CHO) amount and type on glucose levels is especially important in GDM. Dietary CHO are diverse, ranging from simple sugars to longer-chain oligo- and poly- saccharides which have diverse effects on blood glucose, microbial fermentation and bowel function. Studies have established that dietary CHO amount and type can impact maternal glucose and nutritional recommendations advise women with GDM to limit total intake or choose complex and low glycemic CHO. However, robust maternal and infant benefits are not consistently shown. Novel approaches which help women with GDM adhere to dietary recommendations such as diabetes-specific meal replacements (which provide a defined and complete nutritional composition with slowly-digested CHO) and continuous glucose monitors (which provide unlimited monitoring of maternal glycemic fluctuations) have shown benefits on both maternal and neonatal outcomes. Continued research is needed to understand and develop tools to facilitate patient adherence to treatment goals, individualize interventions and improve outcomes.

Impact of malnutrition on survival and healthcare utilization in Medicare beneficiaries with diabetes: a retrospective cohort analysis.

OBJECTIVE: The aim of this study was to examine the impact of pre-existing malnutrition on survival and economic implications in elderly patients with diabetes. RESEARCH DESIGN AND METHODS: A retrospective observational study was conducted to examine the impact of malnutrition with or without other significant health conditions on survival time and healthcare costs using the Centers for Medicare and Medicaid Services (CMS) data from 1999 to 2014 for beneficiaries with a confirmed first date of initial diagnosis of diabetes (n=15 121 131). The primary outcome was survival time, which was analyzed using all available data and after propensity score matching. Healthcare utilization cost was a secondary outcome. RESULTS: A total of 801 272 beneficiaries were diagnosed with malnutrition. The analysis on propensity score-matched data for the effect of common conditions on survival showed that the risk for death in beneficiaries with diabetes increased by 69% in malnourished versus normo-nourished (HR, 1.69; 99.9% CI 1.64 to 1.75; P<0.0001) beneficiaries. Malnutrition increased the risk for death within each of the common comorbid conditions including ischemic heart disease (1.63; 1.58 to 1.68), chronic obstructive pulmonary disorder (1.60; 1.55 to 1.65), stroke or transient ischemic attack (1.57; 1.53 to 1.62), heart failure (1.54; 1.50 to 1.59), chronic kidney disease (1.50; 1.46 to 1.55), and acute myocardial infarction (1.47; 1.43 to 1.52). In addition, the annual total spending for the malnourished beneficiaries was significantly greater than that for the normo-nourished beneficiaries ($36 079 vs 20 787; P<0.0001). CONCLUSIONS: Malnutrition is a significant comorbidity affecting survival and healthcare costs in CMS beneficiaries with diabetes. Evidence-based clinical decision pathways need to be developed and implemented for appropriate screening, assessment, diagnosis and treatment of malnourished patients, and to prevent malnutrition in normo-nourished patients with diabetes.

Isokinetic Dynamometry in Healthy Versus Sarcopenic and Malnourished Elderly: Beyond Simple Measurements of Muscle Strength.

This study quantified systematic and intraindividual variability among three repetitions of concentric isokinetic knee extension and flexion tests to determine velocity-related differences in peak torque (PT) and mean power (MP) in healthy elderly (HE) versus sarcopenic and malnourished elderly (SME). In total, 107 HE ( n = 54 men, n = 53 women) and 261 SME ( n = 101 men, n = 160 women) performed three maximal concentric isokinetic knee extension and flexion repetitions at 60°·s-1 and 180°·s-1. PT for Repetition 3 was lower than Repetitions 1 and 2, while MP for Repetition 1 was lower than Repetitions 2 and 3 in SME. Intraindividual variability among repetitions was correlated with strength, but not age, and was greater in SME, during knee flexion, and at 180°·s-1. Velocity-related decreases in PT from 60°·s-1 to 180°·s-1 were more pronounced in SME. In summary, (a) the repetition with the highest PT value may be the best indicator of maximal strength, while the average may indicate strength maintenance in SME; (b) intraindividual variability among repetitions reflects functional decrements from HE to SME; and

Impacts of High-Protein Oral Nutritional Supplements Among Malnourished Men and Women with Sarcopenia: A Multicenter, Randomized, Double-Blinded, Controlled Trial.

BACKGROUND: Recent evidence suggests that nutritional interventions may improve muscle outcomes in malnutrition and sarcopenia. OBJECTIVES: We evaluated the effects of 2 high-quality oral nutritional supplements (ONS) differing in amount and type of key nutrients in older adult men and women. DESIGN: A multicenter, randomized, double-blinded, controlled clinical trial. PARTICIPANTS: Malnourished and sarcopenic men and women, 65 years and older (n = 330). INTERVENTION: A 24-week intervention period with 2 energy-rich (330 kcal) ONS treatment groups: Control ONS (CONS, 14 g protein; 147 IU vitamin D3) versus Experimental ONS (EONS, 20 g protein; 499 IU vitamin D3; 1.5 g CaHMB) taken twice daily. Both ONS also contained other vitamins, minerals, and nutrients in varying amounts. MEASUREMENTS: Isokinetic peak torque (PT, Nm) leg strength, grip strength (kg), and gait speed (m·s-1) were assessed at baseline and 12 and 24 weeks. Left and right leg muscle mass (LMM, kg) were assessed by dual-energy x-ray absorptiometry (DXA). Muscle quality (MQ) was leg strength expressed relative to the tested LMM (Nm·kg-1). Subgroup analyses were performed: severe sarcopenia (low skeletal mass index, low grip strength [<30 kg men; <20 kg women], low gait speed [<0.8 m·s-1]) and mild-moderate sarcopenia (low skeletal mass index, normal gait speed, or normal grip strength). RESULTS: Both ONS groups (EONS and CONS) improved PT, MQ, grip strength, and gait speed from baseline with no treatment differences. Those with severe sarcopenia (44%) exhibited lower baseline PT and MQ, with no differences in strength improvements between treatments. However, participants with mild-moderate sarcopenia exhibited higher baseline PT and MQ, with differences in strength improvements at 12 weeks (EONS > CONS, P = .032) in those with normal grip strength. There were no treatment differences based on sarcopenic severity for either grip strength or gait speed. CONCLUSION: ONS improved strength outcomes in malnourished older adults with sarcopenia. In those with mild-moderate sarcopenia, but not severe sarcopenia, consumption of the EONS improved leg muscle strength and quality compared with the standard CONS.

Effect of calcium ß-hydroxy-ß-methylbutyrate (CaHMB) with and without resistance training in men and women 65+yrs: a randomized, double-blind pilot trial.

BACKGROUND: Evidence suggests CaHMB may impact muscle mass and/or strength in older adults, yet no long-term studies have compared its effectiveness in sedentary and resistance training conditions. The purpose of this study was to evaluate the effects of 24 weeks of CaHMB supplementation and resistance training (3 d wk(-1)) or CaHMB supplementation only in ≥65 yr old adults. METHODS: This double-blinded, placebo-controlled, trial occurred in two phases under ad libitum conditions. Phase I consisted of two non-exercise groups: (a) placebo and (b) 3 g CaHMB consumed twice daily. Phase II consisted of two resistance exercise groups: (a) placebo and resistance exercise and (b) 3 g CaHMB consumed twice daily and resistance exercise (RE). Strength and functionality were assessed in both phases with isokinetic leg extension and flexion at 60°·s(-1) and 180°·s(-1) (LE60, LF60, LE180, LF180), hand grip strength (HG) and get-up-and-go (GUG). Dual X-Ray Absorptiometry (DXA) was used to measure arm, leg, and total body lean mass (LM) as well as total fat mass (FM). Muscle Quality was measured for arm (MQ(HG)=HG/arm LM) and Leg (MQ60=LE60/leg LM) (MQ180=LE180/leg LM). RESULTS: At 24 weeks of Phase I, change in LE60 (+8.8%) and MQ180 (+20.8%) for CaHMB was significantly (p<0.05) greater than that for placebo group. Additionally, only CaHMB showed significant (p<0.05) improvements in total LM (2.2%), leg LM (2.1%), and LE180 (+17.3%), though no treatment effect was observed. Phase II demonstrated that RE significantly improved total LM (4.3%), LE60 (22.8%), LE180 (21.4%), HG (9.8%), and GUG (10.2%) with no difference between treatment groups. At week 24, only CaHMB group significantly improved FM (-3.8%) and MQHG (7.3%); however there was no treatment main effect for these variables. CONCLUSION: CaHMB improved strength and MQ without RE. Further, RE is an effective intervention for improving all measures of body composition and functionality.

A diabetes-specific enteral formula improves glycemic variability in patients with type 2 diabetes.

BACKGROUND: Well-controlled studies have demonstrated that inpatient hyperglycemia is an indicator of poor clinical outcomes, but the use of diabetes-specific enteral formulas in hospitalized patients remains a topic of great debate. METHODS: In two different protocols, postprandial glycemia and insulinemia were measured in 22 subjects with diabetes fed a diabetes-specific or standard formula (protocol 1). Continuous glucose monitoring was used to assess glucose levels in 12 enterally fed patients with diabetes receiving the standard formula followed by the diabetes-specific formula continuously for 5 days each (protocol 2). End points included postprandial glycemia and insulinemia, glycemic variability (mean amplitude of glycemic excursions [MAGE]), mean glucose, and insulin use. RESULTS: In the postprandial response protocol, the diabetes-specific formula resulted in lower positive areas under the postprandial curve (P < 0.001) and peak glucose (P < 0.001) and insulin (P = 0.017) levels. In the protocol using continuous glucose monitoring, glycemic variability (as measured by MAGE) was lower with continuous administration of the diabetes-specific than the standard formula (64.6 +/- 6.8 mg/dL vs. 110.6 +/-15.3 mg/dL, P = 0.003). Also, administration of the diabetes-specific formula resulted in lower mean glucose concentrations during feeding (171.1 +/- 16.1 vs. 202.1 +/- 17.4 mg/dL, P = 0.024) and insulin requirements (7.8 +/- 2.3 vs. 10.9 +/- 3.3 units/day, P = 0.039) than the standard formula. CONCLUSIONS: Relative to the standard formula, the diabetes-specific formula reduced postprandial glycemia, mean glucose, glycemic variability, and short-acting insulin requirements. These results suggest potential clinical usefulness of a diabetes-specific enteral formula for minimizing glycemic excursions in hospitalized patients.

Economic analysis of a diabetes-specific nutritional meal replacement for patients with type 2 diabetes.

This study extends nutritional intervention results reported by short-term clinical trials of a diabetes-specific nutritional meal replacement by assessing the ten-year impact of the interventions on patient outcomes and costs compared to usual care. We developed and validated a computer simulation of type 2 diabetes based on published data from major clinical trials. The model tracks patients through microvascular and macrovascular health states and reports cumulative costs and quality adjusted life years. We modeled different scenarios that include a diabetes-specific nutritional meal replacement as part of a structured lifestyle intervention, and also as the only difference between the intervention and usual care treatment groups, and compared them to usual care with diet and physical activity recommendations. We used sensitivity analysis to explore the robustness of results. When a diabetes-specific nutritional meal replacement is the only treatment difference and is considered an equal cost meal replacement, the diabetes-specific nutritional meal replacement interventions are less costly and more effective than usual care. As an added cost meal replacement, the diabetes-specific nutritional meal replacement has an incremental cost-effectiveness ratio between $50,414 and $55,036 depending on improvement in percent glycated hemoglobin. A hypothetical lifestyle intervention using a diabetes-specific nutritional meal replacement has an incremental cost-effectiveness ratio of $47,917. The diabetes-specific nutritional meal replacement was found to be cost-effective under the various conditions simulated.

An integrated intervention program to control diabetes in overweight Chinese women and men with type 2 diabetes.

This study evaluated a structured and integrated intervention program on diabetes management in individuals with type 2 diabetes in Shanghai, China. Men and women with type 2 diabetes and body mass index > 23 kg/m2 were randomized into a 24-week, prospective, randomized clinical trial. The Reference Group (n=50) received diabetes education including diet and physical activity instruction only; the Intervention Group (n=100) received more intensive intervention, including diabetes education with frequent blood glucose monitoring, nutritional counseling, meal plans with diabetes-specific nutritional meal replacement, and weekly progress updates with study staff. Major study assessments were obtained at baseline, and after 12 and/or 24 weeks of intervention. The Intervention Group improved fasting blood glucose, insulin, systolic and diastolic blood pressures compared to Reference Group ( p <0.05). Importantly, HbA1c was lower ( p <0.001) in the Intervention Group at 12 weeks (-0.6 +/- 0.1%) and 24 weeks (-0.8 +/- 0.1%). Weight loss was modest, but significant differences were observed between groups ( p <0.05). Weight change from baseline after 12 and 24 weeks was -2.8 +/- 0.2% and -3.7 +/- 0.3%, respectively, in the Intervention Group vs -1.8 +/- 0.4% and -2.5 +/- 0.4% in the Reference Group. Additionally, waist and hip circumferences and waist:hip ratio decreased in the Intervention compared to the Reference Group ( p <0.05). In conclusion, this study demonstrates that Chinese men and women with type 2 diabetes following an integrated intervention program including diabetes education, frequent blood glucose monitoring and daily use of a diabetes-specific meal replacement, can achieve significant improvements in glycemic control and markers of cardiovascular health.

Effect of two carbohydrate-modified tube-feeding formulas on metabolic responses in patients with type 2 diabetes.

OBJECTIVES: This study evaluated the glycemic, insulinemic, and glucagon-like peptide-1 (GLP-1) responses of subjects with type 2 diabetes mellitus to consumption of two diabetes-specific tube-feeding formulas (slowly digested carbohydrate formula [SDC] and diabetes-specific formula [DSF]) and one formula intended for individuals without diabetes (standard formula [STND]). METHODS: Forty-eight subjects controlled with diet and/or oral antihyperglycemic medications received the SDC, DSF, and STND. Postprandial glucose, insulin, and GLP-1 were measured on three occasions after an overnight fast in a double-blinded, randomized, three-treatment, crossover design. RESULTS: The positive area under the curve for glucose and insulin with the STND was higher (P < 0.001) compared with the SDC and DSF. The adjusted GLP-1 concentration at 60 min was higher for the SDC compared with the DSF and STND (P < 0.05). CONCLUSION: Both lower-carbohydrate diabetes-specific formulas resulted in a lower postprandial blood glucose response compared with the STND. The formula also rich in slowly digested carbohydrate and monounsaturated and omega-3 fatty acids (SDC) produced significantly lower blood glucose and insulin responses and higher levels of GLP-1 in the presence of significantly lower insulin concentrations. These results support the view that the quantity and quality of carbohydrate and fat may play important roles in the management of patients with type 2 diabetes mellitus and could result in improved beta-cell function over the long term.

Extract of Salacia oblonga lowers acute glycemia in patients with type 2 diabetes.

BACKGROUND: Two previous studies tested the efficacy of Salacia oblonga extract in healthy adults. OBJECTIVE: This study evaluated the effect of an herbal extract of Salacia oblonga on postprandial glycemia and insulinemia in patients with type 2 diabetes after ingestion of a high-carbohydrate meal. DESIGN: Sixty-six patients with diabetes were studied in this randomized, double-blinded crossover study. In a fasted state, subjects consumed 1 of the following 3 meals: a standard liquid control meal, a control meal + 240 mg Salacia oblonga extract, and a control meal + 480 mg Salacia oblonga extract. Serum glucose and insulin samples were measured at baseline and at postprandial intervals up to 180 min. RESULTS: Both doses of the Salacia extract significantly lowered the postprandial positive area under the glucose curve (14% for the 240 mg extract and 22% for the 480 mg extract) and the adjusted peak glucose response (19% for the lower dose and 27% for the higher dose of extract) to the control meal. In addition, both doses of the herbal extract significantly decreased the postprandial insulin response, lowering both the positive area under the insulin curve and the adjusted peak insulin response (14% and 9%, respectively, for the 240 mg extract; 19% and 12%, respectively, for the 480 mg extract) in comparison with the control meal. CONCLUSIONS: The extract of Salacia oblonga lowers acute glycemia and insulinemia in persons with type 2 diabetes after a high-carbohydrate meal. The results from this study suggest that Salacia may be beneficial to this population for postprandial glucose control.

Differential effects of n-3 polyunsaturated fatty acids on metabolic control and vascular reactivity in the type 2 diabetic ob/ob mouse.

Diets rich in monounsaturated fatty acids (MUFA) are recommended for individuals with type 2 diabetes mellitus (T2DM). The American Heart Association recommends increasing intakes of n-3 polyunsaturated fatty acids (PUFA) to reduce the risk of vascular disease in high-risk individuals; however, the long-term effects of these bioactive fatty acids on glucose metabolism in insulin resistance are controversial. The present studies were conducted to evaluate the effects of diets rich in both MUFA and alpha linolenic acid (C18:3n-3, ALA), eicosapentaenoic acid (C20:5n-3, EPA), or docosahexaenoic acid (C22:6n-3, DHA), on glycemic control and other parameters related to vascular health in a mouse model of T2DM and insulin resistance. Male ob/ob mice (n = 15 per treatment) were fed 1 of 4 lipid-modified formula diets (LFDs) for 4 weeks: (1) MUFA control, (2) ALA blend, (3) EPA blend, and (4) DHA blend. A portion of a MUFA-rich lipid blend in the control LFD was replaced with 11% to 14% energy as n-3 PUFA. After 4 weeks, plasma glucose response to a standard meal (1.5 g carbohydrate/kg body weight) and insulin challenge (2 U/kg body weight, IP) was assessed, and samples were collected for analysis of glucose, insulin, and lipids. Vascular reactivity of isolated aortic rings was assessed in an identical follow-up study. The results showed that insulin-resistant mice fed an LFD with EPA and/or DHA blends had significantly (P < .05) lower triglycerides and free fatty acids, but insulin sensitivity and fasting plasma glucose were not improved. However, mice fed with the ALA blend had significantly improved insulin sensitivity when compared to those fed with other LFD (P < .05). Animals fed an LFD with n-3 PUFA from marine or plant sources showed significantly improved vascular responses as compared with the MUFA-rich LFD (E(max), P < .05) and ob/ob reference mice consuming chow (E(max) and pEC(50), P < .05). In summary, long-term consumption of LFD with n-3 PUFAs improved blood lipids and vascular function in an animal model of insulin resistance and T2DM; however, only MUFA-rich LFD with ALA also improved both insulin sensitivity and glycemic responses. Further studies of MUFA-rich LFD with ALA with individuals who have T2DM are warranted.

Supplementation with 3 compositionally different tocotrienol supplements does not improve cardiovascular disease risk factors in men and women with hypercholesterolemia.

BACKGROUND: Tocotrienols have been reported to lower LDL-cholesterol and fasting glucose concentrations and to have potent antioxidant effects, but the results are contradictory. OBJECTIVE: The objective was to study the relative effect of tocotrienol supplements of different compositions (mixed alpha- plus gamma-, high gamma-, or P25-complex tocotrienol) on blood lipids, fasting blood glucose, and the excretion of 8-iso-prostaglandin F(2alpha), a measure of oxidative stress, in healthy hypercholesterolemic men and women. DESIGN: This was a double-blind, randomized, parallel-design study in which subjects (n = 67 men and women) consumed 1 of 3 commercially available tocotrienol supplements or a safflower oil placebo for 28 d. Blood and urine samples were obtained before and after the 28-d supplementation phase for analysis of fasting blood lipids, glucose, tocotrienols and tocopherols, and 8-iso-prostaglandin F(2alpha). RESULTS: Overall, serum tocotrienols were increased in subjects who consumed tocotrienols, which showed that the putatively active components were absorbed. No significant differences in mean lipid or glucose concentrations were observed among the 4 treatment groups at the end of the 28-d supplementation phase. However, when the values were expressed as a percentage change from the concentrations during the presupplementation run-in phase, LDL cholesterol increased slightly (7 +/- 2%) but significantly (P < 0.05) in the group consuming the mixed alpha- plus gamma-tocotrienol supplement when compared with LDL cholesterol in the group consuming the P25-complex tocotrienol. Neither mean concentrations nor the percentage change in 8-iso-prostaglandin F(2alpha) differed significantly among treatments. CONCLUSION: Supplementation with 200 mg tocotrienols/d from 3 commercially available sources has no beneficial effect on key cardiovascular disease risk factors in highly compliant adults with elevated blood lipid concentrations.