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Phenolic-rich plant extracts have been demonstrated to improve glycemic control in individuals with prediabetes. However, there is increasing evidence that people with prediabetes are not a homogeneous group but exhibit different glycemic profiles leading to the existence of prediabetes subgroups. Prediabetes subgroups have been identified as: isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), and combined impaired fasting glucose and glucose intolerance (IFG/IGT). The present review investigates human clinical trials examining the hypoglycemic potential of phenolic-rich plant extracts in prediabetes and prediabetes subgroups. Artemisia princeps Pampanini, soy (Glycine max (L.) Merrill) leaf and Citrus junos Tanaka peel have been demonstrated to improve fasting glycemia and thus may be more useful for individuals with IFG with increasing hepatic insulin resistance. In contrast, white mulberry (Morus alba Linn.) leaf, persimmon (Diospyros kaki) leaf and Acacia. Mearnsii bark were shown to improve postprandial glycemia and hence may be preferably beneficial for individuals with IGT with increasing muscle insulin resistance. Elaeis guineensis leaf was observed to improve both fasting and postprandial glycemic measures depending on the dose. Current evidence remains scarce regarding the impact of the plant extracts on glycemic control in prediabetes subgroups and therefore warrants further study.

An acute, placebo-controlled, single-blind, crossover, dose-response, exploratory study was designed to investigate the hypoglycaemic effects of New Zealand pine bark extract (Enzogenol&reg, ). Twenty-five healthy participants categorised into having a monophasic or complex (biphasic or triphasic) glucose curve shape at the control visit consumed a placebo and Enzogenol&reg, (50 and 400 mg) on three separate occasions before an oral glucose tolerance test (OGTT). In the monophasic group, 50 and 400 mg of Enzogenol&reg, significantly reduced the mean glucose incremental area under the curve (iAUC) compared to control 241.3 &plusmn, 20.2 vs. 335.4 &plusmn, 34.0 mmol/L&middot, min, p = 0.034 and 249.3 &plusmn, 25.4 vs. 353.6 &plusmn, 31.5 mmol/L&middot, min, p = 0.012, respectively. The 400 mg dose further reduced the percentage increment of postprandial glucose (%PG) 31.4% &plusmn, 7.9% vs. 47.5% &plusmn, 8.6%, p = 0.010, glucose peak 7.9 &plusmn, 0.3 vs. 8.9 &plusmn, 0.3 mmol/L, p = 0.025 and 2h-OGTT postprandial glucose (2hPG) 6.1 &plusmn, 0.3 vs. 6.7 &plusmn, 0.3 mmol/L, p = 0.027. Glucose iAUC was not significantly different in the complex group, except for reductions in %PG 28.7% &plusmn, 8.2% vs. 43.4% &plusmn, 5.9%, p = 0.012 after 50 mg dose and 27.7% &plusmn, 5.4% vs. 47.3% &plusmn, 7.2%, p = 0.025 after 400 mg dose. The results suggest that Enzogenol&reg, may have hypoglycaemic effects in healthy participants, especially those exhibiting monophasic shapes.

Background: Plant extracts may help to improve glycemic control in individuals with poor glycemic control. However, few studies have been investigated in the prediabetes cohort, which is a high-risk condition for T2DM. Thus, this study aimed to investigate the acute effect of grape seed, rooibos tea, and olive leaf extracts on postprandial blood glucose and insulin in participants with prediabetes. Methods: An acute, single-blind, placebo-controlled, non-randomized, crossover study (ACTRN12617000837325) where placebo and extracts of grape seed, rooibos tea and olive leaf standardized for total antioxidant capacity were given separately during an oral glucose tolerance test to participants (n=19, five men and fourteen women, aged 65.0 ± 1.6 years, Body Mass Index (BMI) 27.3 ± 1.1 kg/m 2 ) with prediabetes (Glycated hemoglobin A1c (HbA1c) 42 ± 1 mmol/mol). The primary outcome incremental area under the curve of glucose (iAUC glucose ) was examined with other glycemic measures. Data was analyzed using linear mixed model for repeated measures. Secondary analysis was conducted by stratifying participants into either a healthier or less healthy subgroup based on the postprandial time to glucose and insulin peaks, with the less healthy subgroup experiencing delayed glucose and/or insulin peaks. Results: There were no overall significant changes to glucose and insulin measures between all plant extracts and placebo ( p >0.05). Upon secondary analysis, all extracts affected glycemic responses in the less healthy subgroup. Compared to placebo, grape seed reduced plasma iAUC glucose ( p =0.016, 21.9% reduction), 2 h postprandial glucose (2hPG) ( p =0.034, 14.7% reduction) and metabolic clearance rate of glucose (MCR glucose ) ( p =0.016, 16.7% increase). It also improved insulin indices such as 2 h postprandial insulin (2hPI) ( p =0.029, 22.4% reduction) and Stumvoll overall insulin sensitivity index (ISI overall ) ( p =0.028, 15.0% increase). Rooibos tea extract significantly improved β-cell function as demonstrated by the increased oral disposition index (DI) ( p =0.031, 32.4% increase) compared to placebo. Olive leaf extract significantly increased incremental area under the curve of insulin (iAUC insulin ) ( p =0.040, 16.7% increase). Conclusion: Grape seed, rooibos tea and olive leaf extracts demonstrated acute hypoglycemic benefits in adults with prediabetes and having less healthy metabolic profiles. A chronic study on the plant extracts is warranted to determine their longer-term impact on prediabetes. Trial Registration ID: ACTRN12617000837325 Keywords: grape seed extract; rooibos tea extract; olive leaf extract; impaired glycemic control; hyperglycemia; hypoglycemic effects; insulin sensitivity; beta-cell function

OBJECTIVES: To explore indicators of T2DM risk in a multi-ethnic group of children, using HbA1c as the dependent variable. METHODS: This data was from a subset of the 730 children recruited for the Children's Bone Study, a cross-sectional study of 8–11 year-old children in Auckland, New Zealand. Glycated haemoglobin (HbA1c) was measured from a finger-prick blood test (Roche Cobas). Anthropometry included weight, height, waist-to-height ratio (WtHR) and percentage body fat (%BF). Ethnicity, gender, age, and physical activity (PA) were assessed by questionnaires completed by the parents or guardians. Regression analysis was used to explore which independent variables best predicted variance in HbA1c. RESULTS: When children (n = 451, 10.4 + 0.6 years, 45% male) were classified by glycaemic status, 71 (15.7%) had HbA1c levels indicative of prediabetes (> 39mmol/mol), with Pacific (n = 29, 27.4%) and South Asian (n = 13, 29.5%) children, more likely to be prediabetic compared to European children (n = 10, 6.3%) (P 39mmol/mol, although the majority of Pacific children were in the at risk group. CONCLUSIONS: South Asian and Pacific Island adults are at high risk of T2DM compared with the total New Zealand population. The prevalence of elevated HbA1c in children of these ethnicities suggests that the risk is present early in life, supporting the need for early identification and interventions in childhood to halt the progression to T2DM. FUNDING SOURCES: Massey University Research Fund.

Increasing fruit and vegetable consumption is a key lifestyle modification in the prevention and treatment of hypertension. Kiwifruit has previously been shown to have favorable effects on blood pressure (BP), likely through inhibiting angiotensin I-converting enzyme activity. We hypothesized that the replacement of 2 fruit servings in a healthy diet with 2 green kiwifruit a day would significantly improve BP and other markers of cardiovascular function, including heart rate, stroke volume, cardiac output, and total peripheral resistance, in a group of hypercholesterolemic men. Using a controlled cross-over study design, 85 subjects completed a 4-week healthy diet run-in period before randomization to one of two 4-week intervention sequences in which they either consumed 2 green kiwifruit a day plus a healthy diet (intervention) or consumed a healthy diet alone (control). Blood pressure and other measures of cardiovascular function (using a Finometer MIDI [Finapres Medical Systems B.V, Amsterdam, The Netherlands] and standard oscillometric device) and anthropometric measurements were taken before and at the end of the treatment periods. A physical activity questionnaire was completed during the last visit. Subjects were found to be predominantly normotensive (43.5%) or prehypertensive (50.6%) and quite physically active (>30 minutes of moderate to vigorous physical activity/day in >80% subjects). No significant differences were seen for BP or any of the other markers, including heart rate, stroke volume, cardiac output, and total peripheral resistance. In conclusion, in this hypercholesterolemic, nonhypertensive group, no beneficial effects on BP or other markers of cardiovascular function were seen when consuming 2 kiwifruit a day against the background of a healthy diet.

Kiwifruit has the potential to improve markers of metabolic dysfunction, but the response may be influenced by inflammatory state. We aimed to investigate whether inflammatory state would modulate the effect of consuming two green kiwifruit daily on plasma lipids and markers of inflammation.Eighty-five hypercholesterolaemic men completed a 4-week healthy diet run-in, before randomisation to a controlled cross-over study of two 4-week interventions of two green kiwifruit/day plus healthy diet (intervention) or healthy diet alone (control). Anthropometric measures and fasting blood samples (plasma lipids, serum apolipoproteins A1 and B, high-sensitivity C-reactive protein (hs-CRP) and interleukin (IL)-6, tumour necrosis factor-alpha (TNF-α) and IL-10) were taken at baseline, 4 and 8 weeks. Subjects were divided into low and medium inflammatory groups, using pre-intervention hs-CRP concentrations (hs-CRP1 and 1-3 mg/L, respectively). In the medium inflammatory group the kiwifruit intervention resulted in significant improvements in plasma high-density lipoprotein cholesterol (HDL-C) (mean difference 0.08 [95% CI: 0.03, 0.12] mmol/L [P0.001]), total cholesterol (TC)/HDL-C ratio (-0.29 [-0.45, -0.14] mmol/L [P = 0.001]), plasma hs-CRP (-22.1 [-33.6, -4.97]% [P = 0.01]) and IL-6 (-43.7 [-63.0, -14.1]% [P = 0.01]) compared to control treatment. No effects were seen in the low inflammatory group. There were significant between inflammation group differences for TC/HDL-C (P = 0.02), triglyceride (TG)/HDL-C (P = 0.05), and plasma IL-6 (P = 0.04).Inflammatory state modulated responses to the kiwifruit intervention by improving inflammatory markers and lipid profiles in subjects with modestly elevated CRP, suggesting this group may particularly benefit from the regular consumption of green kiwifruit. Registered 16th March 2010, Australian New Zealand Clinical Trials Registry (no. ACTRN12610000213044), www.ANZCTR.org.au.

Fruit and vegetables are key elements of a cardioprotective diet, but benefits on plasma lipids, especially HDL-cholesterol (HDL-C), are inconsistent both within and between studies. In the present study, we investigated whether four selected HDL-C-related polymorphisms (cholesteryl ester transfer protein (CETP) Taq1B, APOA1 − 75G/A, hepatic lipase (LIPC) − 514C → T, and endothelial lipase (LIPG) I24582) modulate the plasma lipid response to a kiwifruit intervention. This is a retrospective analysis of data collected during a 12-week randomised controlled cross-over trial. A total of eighty-five hypercholesterolaemic men completed a 4-week healthy diet run-in period before being randomised to one of two 4-week intervention sequences of two green kiwifruit/d plus healthy diet (kiwifruit intervention) or healthy diet alone (control intervention). The measurement of anthropometric parameters and collection of fasting blood samples were carried out at baseline 1 and after the run-in (baseline 2) and intervention periods. At baseline 2, B1/B1 homozygotes of the CETPTaq1B gene had significantly higher total cholesterol:HDL-C, TAG:HDL-C, and apoB:apoA1 ratios and small-dense LDL concentrations than B2 carriers. A significant CETP Taq1B genotype × intervention interaction was observed for the TAG:HDL-C ratio (P= 0·03). B1/B1 homozygotes had a significantly lower TAG:HDL-C ( − 0·23 (sd 0·58) mmol/l; P= 0·03) ratio after the kiwifruit intervention than after the control intervention, whereas the ratio of B2 carriers was not affected. The lipid response was not affected by other gene polymorphisms. In conclusion, the significant decrease in the TAG:HDL-C ratio in B1/B1 homozygotes suggests that regular inclusion of green kiwifruit as part of a healthy diet may improve the lipid profiles of hypercholesterolaemic men with this genotype.

Exploration of dietary pattern associations within a multi-ethnic society context has been limited. We aimed to describe dietary patterns of 5664 pregnant women from the Growing Up in New Zealand study, and investigate associations between these patterns and maternal socio-demographic, place of birth, health and lifestyle factors. Participants completed a food frequency questionnaire prior to the birth of their child. Principal components analysis was used to extract dietary patterns and multivariable analyses used to determine associations. Four dietary components were extracted. Higher scores on, ‘Junk’ and ‘Traditional/White bread’, were associated with decreasing age, lower educational levels, being of Pacific or Māori ethnicity and smoking. Higher scores on, ‘Health conscious’ and ‘Fusion/Protein’, were associated with increasing age, better self-rated health, lower pre-pregnancy body mass index (BMI) and not smoking. Higher scores on ‘Junk’ and ‘Health conscious’ were associated with being born in New Zealand (NZ), whereas higher scores on ‘Fusion/Protein’ was associated with being born outside NZ and being of non-European ethnicity, particularly Asian. High scores on the ‘Health conscious’ dietary pattern showed the highest odds of adherence to the pregnancy dietary guidelines. In this cohort of pregnant women different dietary patterns were associated with migration, ethnicity, socio-demographic characteristics, health behaviors and adherence to dietary guidelines.

The unique composition of green kiwifruit has the potential to benefit CVD risk. The aim of the present study was to investigate the effect of consuming two green kiwifruits daily in conjunction with a healthy diet on plasma lipids and other metabolic markers and to examine response according toAPOEgenotype in hypercholesterolaemic men. After undergoing a 4-week healthy diet, eighty-five hypercholesterolaemic men (LDL-cholesterol (LDL-C) >3·0 mmol/l and TAG P= 0·004) and the total cholesterol (TC):HDL-C ratio was significantly lower (mean difference − 0·15; 95 % CI − 0·24, − 0·05 mmol/l;P= 0·002) compared with the control. In carriers of theAPOE4allele, TAG decreased significantly (mean difference − 0·18; 95 % CI − 0·34, − 0·02 mmol/l;P= 0·03) with kiwifruit compared with control. There were no significant differences between the two interventions for plasma TC, LDL-C, insulin, glucose, hs-CRP and BP. The small but significant increase in HDL-C and decrease in TC:HDL-C ratio and TAG (inAPOE4carriers) suggest that the regular inclusion of green kiwifruit as part of a healthy diet may be beneficial in improving the lipid profiles of men with high cholesterol.

Asian Indians are an at-risk group for vitamin B12 deficiency (because of vegetarianism) and insulin resistance (IR). Vegetarianism and consequent vitamin B12 deficiency may be associated with IR. This study aimed to describe the vitamin B12 status of predominantly overweight/obese women of South Asian origin living in Auckland and to correlate serum vitamin B12 and vegetarian status with IR as part of the larger Surya Study looking at health and lifestyle in this population.This was a cross-sectional study of 135 women at least 20 y of age who were not taking vitamin B supplements or medications that could affect vitamin B12 concentrations (serum vitamin B12800 pmol/L). Data collection included serum vitamin B12, serum folate, measurements of IR (HOMA2-IR), and anthropometry. Vegetarian status was established for 124 subjects (90 non-vegetarians, 34 vegetarians).Mean serum vitamin B12 was 227 pmol/L (95% confidence interval 210-245), serum folate was 19.1 nmol/L (18.0-20.2), and HOMA2-IR was 1.24 (1.13-1.36). Non-vegetarians had higher serum vitamin B12 levels (257 pmol/L, 235-281) than vegetarians (181 pmol/L, 159-207), P0.001. Vitamin B12 deficiency (150 pmol/L) in vegetarians was 24% versus 9% in non-vegetarians. Non-vegetarians had increased body mass index (25.9 kg/m², 25.0-26.9, versus 23.9 kg/m², 22.6-25.3), waist circumference (81 ± 10.1 versus 75.8 ± 9.88 cm), and HOMA2-IR levels (1.30, 1.17-1.46, versus 1.00, 0.83-1.22). No correlation was found between serum vitamin B12 and HOMA2-IR. A significant positive correlation between non-vegetarian status and IR disappeared after controlling for body mass index.This study population has a low serum vitamin B12 status, especially if vegetarian. The high rates of observed obesity may have overshadowed any other contributing factor to IR.