Timing and Nutrient Type of Isocaloric Snacks Impacted Postprandial Glycemic and Insulinemic Responses of the Subsequent Meal in Healthy Subjects

The aim of the study was to explore the impact of both the macronutrient composition and snacking timing on the postprandial glycemic insulinemic responses and food intake. Seventeen healthy female volunteers completed the randomized crossover trials. The volunteers were provided a standard breakfast and lunch at 8:00 and 13:00, respectively, and an ad libitum dinner at 18:00. Provided at either 10:30 (midmorning) or 12:30 (preload), the glycemic effects of the three types of 70 kcal snacks, including chicken breast (mid-C and pre-C), apple (mid-A and pre-A), and macadamia nut (mid-M and pre-M), were compared with the non-snack control (CON), evaluated by continuous glucose monitoring (CGM). The mid-M showed increased insulin resistance after lunch compared with CON, while the pre-M did not. The pre-A stabilized the glycemic response in terms of all variability parameters after lunch, while the mid-A had no significant effect on postprandial glucose control. Both the mid-C and pre-C improved the total area under the glucose curve, all glycemic variability parameters, and the insulin resistance within 2 h after lunch compared with CON. The pre-C attained the lowest energy intake at dinner, while the mid-A and the mid-M resulted in the highest. In conclusion, the chicken breast snack effectively stabilized postprandial glycemic excursion and reduced insulin resistance while the macadamia snack did not, regardless of ingestion time. Only as a preload could the apple snack mitigate the glucose response after the subsequent meal.

Real-time Assessment of the Bidirectional Relationship Between Affective States and Glucose: Protocol for a 14-Day Observational Study

BACKGROUND

Glucose variability increases cardiometabolic disease risk. While many factors can influence glucose levels, postprandial glucose response is the primary driver of glucose variability. Furthermore, affect may directly and indirectly impact glucose variability through its effect on eating behavior. Continuous glucose monitors (CGMs) facilitate the real-time evaluation of blood glucose, and ecological momentary assessment (EMA) can be used to assess affect in real time. Together, data collected from these sources provide the opportunity to further understand the role of affect in glucose levels.

OBJECTIVE

This paper presents the protocol for a study that aims to (1) evaluate the feasibility and acceptability of using CGMs along with EMA in nondiabetic populations and (2) examine the bidirectional relationship between affect and glucose in nondiabetic adults with overweight or obesity using a CGM and EMA.

METHODS

Eligibility criteria for the study include participants (1) aged 18 to 65 years old, (2) with a BMI of ≥25 kg/m², (3) who are able to read and write in English, and (4) who own a smartphone. Individuals will be excluded if they (1) have type 1 or 2 diabetes or have any other condition that requires glucose monitoring, (2) are pregnant, (3) use any medications that have the potential to alter blood glucose levels or interfere with the glucose sensing process, or (4) have a diagnosed gastrointestinal condition or eating disorder. In a 14-day observational study, participants will wear a FreeStyle Libre Pro CGM sensor (Abbott) and will receive mobile phone-based EMA prompts 6 times per day (randomly within six 2-hour windows between 8 AM and 8 PM) to assess positive and negative affect. Participants will also wear a Fitbit Inspire 2 (Fitbit) to continuously monitor physical activity and sleep, which will be included as covariates in the analysis. Multilevel linear regression models will be used to evaluate the acute relationship between glucose level and affect.

RESULTS

Recruitment started in October 2022 and is expected to be completed in March 2023. We will aim to recruit 100 participants. As of December 12, 2022, a total of 39 participants have been enrolled.

CONCLUSIONS

The results of this study will further elucidate the role of affect in glucose variability. By identifying affective states that may lead to glucose excursions, our findings could inform just-in-time behavioral interventions by indicating opportunities for intervention delivery.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/45104.

Feruloyl Sucrose Esters: Potent and Selective Inhibitors of α-glucosidase and α-amylase

INTRODUCTION

Feruloyl Sucrose Esters (FSEs) are a class of Phenylpropanoid Sucrose Esters (PSEs) widely distributed in plants. They were investigated as potential selective Alpha Glucosidase Inhibitors (AGIs) to eliminate the side effects associated with the current commercial AGIs. The latter effectively lowers blood glucose levels in diabetic patients but causes severe gastrointestinal side effects.

METHODS

Systematic structure-activity relationship (SAR) studies using in silico, in vitro and in vivo experiments were used to accomplish this aim. FSEs were evaluated for their in vitro inhibition of starch and oligosaccharide digesting enzymes α-glucosidase and α-amylase followed by in silico docking studies to identify the binding modes. A lead candidate, FSE 12 was investigated in an STZ mouse model.

RESULTS

All active FSEs showed desired higher % inhibition of α-glucosidase and desired lower inhibition of α-amylase in comparison to AGI gold standard acarbose. This suggests a greater selectivity of the FSEs towards α-glucosidase than α-amylase, which is proposed to eliminate the gastrointestinal side effects. From the in vitro studies, the position and number of the feruloyl substituents on the sucrose core, the aromatic 'OH' group, and the diisopropylidene bridges were key determinants of the % inhibition of α-glucosidase and α-amylase. In particular, the diisopropylidene bridges are critical for achieving inhibition selectivity. Molecular docking studies of the FSEs corroborates the in vitro results. The molecular docking studies further reveal that the presence of free aromatic 'OH' groups and the substitution at position 3 on the sucrose core are critical for the inhibition of both the enzymes. From the in vitro and molecular docking studies, FSE 12 was selected as a lead candidate for validation in vivo. The oral co-administration of FSE 12 with starch abrogated the increase in post-prandial glucose and significantly reduced blood glucose excursion in STZ-treated mice compared to control (starch only) mice.

CONCLUSION

Our studies reveal the potential of FSEs as selective AGIs for the treatment of diabetes, with a hypothetical reduction of side effects associated with commercial AGIs.

Postload glucose spike but not fasting glucose determines prognosis after myocardial infarction in patients without known or newly diagnosed diabetes

BACKGROUND

The effect of postload glucose spikes (PGS), the difference between 2 hour post-load plasma glucose (2hPLPG) and fasting plasma glucose (FPG), on post-myocardial infarction (post-MI) prognosis in nondiabetic patients is unexplored.

METHODS

This is a retrospective cohort analysis of 847 nondiabetic post-MI survivors who underwent a predischarge oral glucose tolerance test (median PGS: 2.4 mmol/L). Patients were divided into the unmatched groups 1 and 2 (PGS ≤ and > 2.4 mmol/L) and the propensity score-matched groups 1M and 2M (355 pairs assembled from the overall cohort), and these groups were compared. Major adverse cardiac events (MACE: death and nonfatal reinfarction) were recorded during follow-up (median: 3.4 years). Event-free survival was compared by the Kaplan-Meier method. Multivariate Cox proportional hazards regression determined the predictors of MACE. C-statistics (change in area under the curve, δAUC), continuous net reclassification improvement (NRI^>0 ), and integrated discrimination improvement (IDI) were used to compare models.

RESULTS

The number of MACE was higher in groups 2 (27.3% vs 14.2%, P < .001) and 2M (24.5% vs 15.5%, P < .001). Event-free survival was worse in groups 2 (hazard ratio [HR] 2.01; 95% CI, 1.49-2.71; P < .001) and 2M (HR 1.63; 95% CI, 1.17-2.27; P = .004). PGS independently predicted MACE-free survival in the whole (HR 1.16; 95% CI, 1.06-1.26; P = .002) and matched cohort (HR 1.12; 95% CI, 1.02-1.24; P = .021). PGS, but not FPG or 2hPPG, improved the predictive performance of the base model (δAUC 0.013, P = .046), with greater improvement seen when PGS was added and compared to 2hPPG (δAUC 0.005, P = .034; NRI^>0 0.2107, P = .013; IDI 0.0042, P = .046).

CONCLUSION

PGS is a better predictor of post-MI prognosis than 2hPPG in nondiabetic patients.

Consuming Carbohydrates after Meat or Vegetables Lowers Postprandial Excursions of Glucose and Insulin in Nondiabetic Subjects

We aimed to examine the effects of variable timing of carbohydrate intake on postprandial glucose and insulin excursion in a diet with the same levels of energy and balance of three major nutrients. The study subjects included 8 healthy individuals, mean age 20.0±1.2 y (4 males and 4 females; mean age, 19.1±0.7 and 20.8±0.9 y, respectively), without a family history of diabetes. They consumed a test meal consisting of three separate plates of rice, vegetables, and meat after an overnight fast. The subjects consumed the three plates in different orders on three different days; the subsequent changes in glucose and insulin levels were measured over a 120-min period. The participants who consumed rice at the end showed a significantly lower increase in glucose and insulin levels after 30 min of consumption than that shown by participants who consumed rice first. The areas under the curves for both glucose and insulin responses over 120 min were the least when rice was consumed last, whereas they were the greatest when rice was consumed first. These findings suggested that consuming carbohydrates at the end of a meal is associated with lower postprandial excursions of glucose and insulin. In conclusion, consuming carbohydrates last following vegetables and meat protects against postprandial excursions of glucose and insulin levels.

Higher circulating adiponectin and lower orosomucoid were associated with postload glucose ≤70 mg/dL, a possible inverse marker for dysglycemia, in young Japanese women

OBJECTIVE

To examine whether serum adiponectin and orosomucoid were associated with postload glucose ≤70 mg/dL during an oral glucose tolerance test (OGTT), termed as postload low glycemia, a possible inverse marker for dysglycemia.

RESEARCH DESIGN AND METHODS

75 g OGTTs were performed with multiple postload glucose and insulin measurements over a 30-120 min period in 168 normal-weight Japanese women (18-24 years). Insulin resistance (IR) and β-cell function inferred from serum insulin kinetics during OGTT, fat mass and distribution by dual-energy X-ray absorptiometry (DXA), serum adiponectin and inflammatory markers were compared cross-sectionally between 39 women with and 129 women without postload low glycemia.

RESULTS

Of 168 women, 161 had normal glucose tolerance. Women with as compared with those without postload low glycemia had lower fasting and postload glycemia despite similar fasting and postload insulinemia. They had higher insulinogenic index (p=0.03) and lower adipose IR (a product of fasting free fatty acid and insulin, p=0.01), although DXA-derived general and central adiposity, the Matsuda Index and homeostasis model assessment-IR did not differ. In addition, they had higher adiponectin and lower orosomucoid (both p<0.001). Multivariate logistic regression analyses revealed that adiponectin (OR: 1.14, 95% CI 1.03 to 1.26, p=0.009) and orosomucoid (0.96, 0.93 to 0.97, p=0.008) were associated with postload low glycemia independently of adipose IR and insulinogenic index.

CONCLUSIONS

Higher adiponectin and lower orosomucoid were associated with 70 or lower mg/dL of postload glucose, a possible inverse marker for dysglycemia, in young women independently of DXA-derived fat mass and distribution, insulin secretion and IR.

Glucose excursions and hypoglycemia in patients with type 2 diabetes treated with mitiglinide/voglibose versus glimepiride: A randomized cross-over trial

BACKGROUND

Glucose excursions and hypoglycemia are associated with cardiovascular complications. However, no studies have evaluated glucose excursions and the frequency of hypoglycemia in patients treated with mitiglinide/voglibose versus glimepiride as add-on to dipeptidyl peptidase-4 inhibitor therapy.

METHODS

This cross-over trial included 20 patients with type 2 diabetes. After initiating vildagliptin 100 mg, patients were randomly assigned to receive mitiglinide 10 mg/voglibose 0.2 mg three times daily for 3 days followed by glimepiride 1 mg once daily for the subsequent 3 days as add-on therapy, or vice versa. Glucose excursions and hypoglycemia frequency were measured using 24-h continuous glucose monitoring. Metabolic profile changes were evaluated using a meal tolerance test.

RESULTS

The mean glucose levels in the mitiglinide/voglibose and glimepiride phases were identical (8.01 vs 8.24 mmol/L, respectively). However, during the mitiglinide/voglibose phase compared with the glimepiride phase, the standard deviation of glucose (1.30 vs 2.10 mmol/L; P < 0.001), mean amplitude of glycemic excursions (3.47 vs 5.28 mmol/L; P < 0.001), M-value (24.6 vs 70.0; P < 0.001), continuous overlapping net glycemic action for a 1-h time interval (22.6 vs 31.0; P < 0.001), and area under the curve >10 mmol/L (0.18 vs 0.52 mmol/L per h; P < 0.001) were significantly lower. Hypoglycemia (glucose <3.8 mmol/L) was not observed during the mitiglinide/voglibose phase, but occurred 0.35 times/day in those taking glimepiride. Moreover, the mitiglinide/voglibose phase had higher premeal and lower post-meal glucose levels than the glimepiride phase.

CONCLUSIONS

Adding mitiglinide/voglibose to vildagliptin therapy results in more efficient postprandial glucose control and less hypoglycemia than adding glimepiride.

Association of serum orosomucoid with 30-min plasma glucose and glucose excursion during oral glucose tolerance tests in non-obese young Japanese women

OBJECTIVE

Inflammatory markers are elevated in insulin resistance (IR) and diabetes. We tested whether serum orosomucoid (ORM) is associated with postload glucose, β-cell dysfunction and IR inferred from plasma insulin kinetics during a 75 g oral glucose tolerance test (OGTT).

RESEARCH DESIGN AND METHODS

75 g OGTTs were performed with multiple postload glucose and insulin measurements over a 30-120 min period in 168 non-obese Japanese women (aged 18-24 years). OGTT responses, serum adiponectin and high-sensitivity C reactive protein (hsCRP) were cross-sectionally analyzed by analysis of variance and then Bonferroni's multiple comparison procedure. Stepwise multivariate linear regression analyses were used to identify most important determinants of ORM.

RESULTS

Of 168 women, 161 had normal glucose tolerance. Postload glucose levels and the area under the glucose curve (AUCg) increased in a stepwise fashion from the first through the third ORM tertile. In contrast, there was no or modest, if any, association with fat mass index, trunk/leg fat ratio, adiponectin, hsCRP, postload insulinemia, the Matsuda index and homeostasis model assessment IR. In multivariable models, which incorporated the insulinogenic index, the Matsuda index and HOMA-IR, 30 min glucose (standardized β: 0.517) and AUCg (standardized β: 0.495) explained 92.8% of ORM variations.

CONCLUSIONS

Elevated circulating orosomucoid was associated with elevated 30 min glucose and glucose excursion in non-obese young Japanese women independently of adiposity, IR, insulin secretion, adiponectin and other investigated markers of inflammation. Although further research is needed, these results may suggest a clue to identify novel pathways that may have utility in monitoring dysglycemia within normal glucose tolerance.

Treatment with novel galactomannan derivative reduces 2-hour postprandial glucose excursions in individuals with type 2 diabetes treated with oral medications and/or insulin

Galactomannan is an insoluble polysaccharide that has been shown to reduce postprandial excursions. We assessed the impact of a novel galactomannan derivative (PAZ320) on the magnitude of 2-hour postprandial glucose excursions in individuals with type 2 diabetes who were being treated with oral medication and/or insulin. Investigators recently reported findings from a single-center, open-label, prospective study that evaluated the efficacy of PAZ320 in 24 subjects with type 2 diabetes who were treated with oral antidiabetic agents and/or insulin. End points included adverse events and area under the curve during 3-hour postprandial glucose excursion (gAUC). Subjects consumed a test meal without PAZ320 at baseline and then ingested low-dose (8 g) and high-dose (16 g) PAZ320 with test meals at subsequent intervention visits. A post hoc analysis was conducted to determine changes in 2-hour postprandial glucose excursions. Among the 20 subjects for whom data were available for all clinic visit test meals, 15 (75%) responded to low-dose, high-dose, or both medication dosages. Low-dose responders (n = 8) experienced clinically significant improvements in 2-hour postprandial glucose excursions from baseline excursions compared with nonresponders (-28.00 ± 25.97 mg/dL vs 23.42 ± 11.45 mg/dL, P = .005). Similar differences were seen in high-dose responders (-28.82 ± 24.26 vs 33.89 ± 20.56 mg/dL, P < .0001). PAZ320 was shown to be safe in all patients studied and effective in controlling postprandial glucose in a large portion of the study population. Additional studies are needed to determine its long-term effects on HbA1c and to further define which subpopulation(s) may respond to PAZ320 therapy.

Effect of eating vegetables before carbohydrates on glucose excursions in patients with type 2 diabetes

The aim of this review was to evaluate whether eating vegetables before carbohydrates could reduce the postprandial glucose, insulin, and improve long-term glycemic control in Japanese patients with type 2 diabetes. We studied the effect of eating vegetables before carbohydrates on postprandial plasma glucose, insulin, and glycemic control for 2.5 y in patients with type 2 diabetes. The postprandial glucose and insulin levels decreased significantly when the patients ate vegetables before carbohydrates compared to the reverse regimen, and the improvement of glycemic control was observed for 2.5 y. We also compared the postprandial glucose and glucose fluctuations assessed by continuous glucose monitoring system for 72-h in patients with type 2 diabetes and subjects with normal glucose tolerance when subjects ate vegetables before carbohydrates and carbohydrates before vegetables in a randomized crossover design. The glycemic excursions and incremental glucose peak were significantly lower when the subjects ate vegetables before carbohydrates compared to the reverse regimen. This evidence supports the effectiveness of eating vegetables before carbohydrates on glucose excursions in the short-term and glycemic control in the long-term in patients with type 2 diabetes.

A novel insulin combination of insulin degludec and insulin aspart achieves a more stable overnight glucose profile than insulin glargine: results from continuous glucose monitoring in a proof-of-concept trial

PURPOSE

Insulin degludec coformulated with insulin aspart (as IDegAsp) can cover 24 h basal insulin and postprandial insulin requirements after a main meal with one injection. We compared glycemic stability following IDegAsp or insulin glargine (IGlar) given before the evening meal in patients with type 2 diabetes.

METHODS

A subset of 112 insulin-naïve type 2 diabetes patients from a randomized, parallel-group trial (IDegAsp versus IGlar, each added to metformin) underwent 72 h continuous interstitial glucose (IG) monitoring after 16 weeks of treatment. End points included mean IG concentrations, 2 h postprandial IG increments and postprandial peak, IG fluctuation (summed area above and below mean IG), within-subject coefficient of variation (day-to-day variation) in mean nocturnal IG, and episodes of low (<3.5 mmol/liter) and high (>10 mmol/liter) IG. Values were derived for the entire 72 h, with the nocturnal interval (0001-0559 h) also assessed.

RESULTS

The postdinner IG increment observed with IGlar did not occur with IDegAsp [IDegAsp - IGlar, -1.42 (-2.15, -0.70) mmol/liter]. Nocturnal IG fluctuation was 21% lower with IDegAsp [IDegAsp/IGlar, 0.79 (0.66, 0.96) mmol/liter], with 48% fewer nocturnal high IG episodes [ratio IDegAsp/IGlar, 0.52 (0.32, 0.87)].

CONCLUSIONS

IDegAsp given with the evening meal reduces postdinner glucose excursion and provides more stable nocturnal glycemia as compared with IGlar.

Impact of glucose excursion and mean glucose concentration in oral glucose-tolerance test on oxidative stress among Japanese Americans

AIM

To evaluate the impact of glucose excursion (GE) and mean glucose concentration (MGC) on oxidative stress among persons with or without diabetes.

MATERIALS AND METHODS

We examined 775 Japanese Americans who had normal glucose tolerance (NGT), impaired glucose tolerance, or diabetes according to the 75 g oral glucose-tolerance test, using fasting, 1-hour, and 2-hour glucose data. We calculated GE by subtracting the minimum from the maximum glucose level among three points and calculated MGC using these measurements. We investigated the relationship between GE or MGC and urinary isoprostane as a marker of oxidative stress.

RESULTS

According to tertiles of GE or MGC, GE was associated with isoprostane levels among subjects with NGT as well as those with diabetes (P=0.004 and 0.033 for trend, respectively). However, MGC was associated with isoprostane only among NGT subjects (P=0.001 for trend). Association between GE and isoprostane was significant when adjustment was made for age, sex, smoking status, body mass index, C-reactive protein, glucose tolerance status, and homeostatic model assessment (P=0.029), but the association with MGC was not significant.

CONCLUSION

Our results suggest the possibility that GE might result in oxidative stress, and the relationship is stronger than that for MGC.