A randomised controlled trial of additional bolus insulin using an insulin-to-protein ratio compared with insulin-to-carbohdrate ratio alone in people with type 1 diabetes following a carbohydrate-restricted diet.

AIMS: Postprandial hyperglycemia can be problematic for people with type 1 diabetes (T1DM) following carbohydrate-restricted diets. Bolus insulin calculated for meal protein plus carbohydrate may help. This study evaluated the effect of additional bolus insulin using an insulin-to-protein ratio (IPR) on glycaemic control. MATERIALS AND METHODS: Participants with T1DM aged ≥18-years were randomly allocated (1:1) to either carbohydrate and protein-based, or carbohydrate-based insulin dosing alone for 12 weeks while following a carbohydrate-restricted diet (50-100 g/day). Measurement of HbA1c and continuous glucose monitoring occurred at baseline and 12 weeks, with assessment of participant experience at 12 weeks. RESULTS: Thirty-four participants were randomised, 22 female, mean(SD): age 39.2 years (12.6) years; diabetes duration 20.6 years (12.9); HbA1c 7.3 % (0.8), 56.7 mmol/mol (9.2). Seven in each group used insulin pump therapy. HbA1c reduced at 12 weeks with no difference between treatments: mean (SD) control 7.2 % (1.0), 55.7 mmol/mol (10.6); intervention 6.9 % (0.7), 52.3 mmol/mol (7.2) (p = 0.65). Using additional protein-based insulin dosing compared with carbohydrate alone, there was no difference in glycaemic variability, time spent in euglycemic range (TIR), or below range. Participants using IPR reported more control of their diabetes, but varying levels of distress. CONCLUSIONS: Additional bolus insulin using an IPR did not improve glycaemic control or TIR in patients with well controlled T1DM following a carbohydrate-restricted diet. Importantly, the use of the IPR does not increase the risk of hypoglycemia and may be preferred.

A very-low-calorie diet (VLCD) intervention for the management of prediabetes and early Type 2 diabetes mellitus in a multi-ethnic cohort in Aotearoa New Zealand: The PROGRESS NZ feasibility study.

BACKGROUND AND OBJECTIVES: Very-low calorie diets (VLCD) achieve weight loss and remission of Type 2 diabetes (T2DM), but efficacy and acceptability in non-European populations is less clear. This feasibility study examines the impact of 10% weight loss through VLCD on metabolic and body composition outcomes in a multi-ethnic cohort of Aotearoa New Zealand (AoNZ) men with prediabetes/early T2DM, and VLCD tolerability/cultural acceptability. METHODS AND STUDY DESIGN: Participants followed a VLCD intervention (mean energy 3033kJ/day) until achievement of 10% weight loss. An oral glucose tolerance test (OGTT), hyperinsulinaemic isoglycaemic clamp with stable isotopes, hood calorimetry and dual-energy Xray absorptiometry (DXA) were undertaken before and after intervention. Qualitative data on VLCD tolerability/cultural acceptability were collected. RESULTS: Fifteen participants were enrolled; nine achieved 10% weight loss. In this group, mean HbA1c reduced by 4.8mmol/mol (2.4-7.1) and reverted to normoglycaemia in n=5/9; mean body weight reduced by 12.0 kg (11.0-13.1) and whole-body glucose disposal improved by 1.5 mg kgFFM-1 min-1 (0.7-2.2). Blood pressure and fasting triglycerides improved significantly. No changes in hepatic glu-cose metabolism were found. In all participants who attended completion testing, HbA1c reduced by 3.4mmol/mol (SD 3.5) and total weight by 9.0kg (SD 5.7). The intervention was highly tolerable/culturally acceptable however challenges with fulfilment of cultural obligations were described. CONCLUSIONS: Results support VLCD use in AoNZ however further work to investigate ethnic differences in physiological response to VLCDs and to optimise protocols for multi-ethnic populations are required.

Tailored Prompting to Improve Adherence to Image-Based Dietary Assessment: Mixed Methods Study.

Background: Accurately assessing an individual's diet is vital in the management of personal nutrition and in the study of the effect of diet on health. Despite its importance, the tools available for dietary assessment remain either too imprecise, expensive, or burdensome for clinical or research use. Image-based methods offer a potential new tool to improve the reliability and accessibility of dietary assessment. Though promising, image-based methods are sensitive to adherence, as images cannot be captured from meals that have already been consumed. Adherence to image-based methods may be improved with appropriately timed prompting via text message. Objective: This study aimed to quantitatively examine the effect of prompt timing on adherence to an image-based dietary record and qualitatively explore the participant experience of dietary assessment in order to inform the design of a novel image-based dietary assessment tool. Methods: This study used a randomized crossover design to examine the intraindividual effect of 3 prompt settings on the number of images captured in an image-based dietary record. The prompt settings were control, where no prompts were sent; standard, where prompts were sent at 7:15 AM, 11:15 AM, and 5:15 PM for every participant; and tailored, where prompt timing was tailored to habitual meal times for each participant. Participants completed a text-based dietary record at baseline to determine the timing of tailored prompts. Participants were randomized to 1 of 6 study sequences, each with a unique order of the 3 prompt settings, with each 3-day image-based dietary record separated by a washout period of at least 7 days. The qualitative component comprised semistructured interviews and questionnaires exploring the experience of dietary assessment. Results: A total of 37 people were recruited, and 30 participants (11 male, 19 female; mean age 30, SD 10.8 years), completed all image-based dietary records. The image rate increased by 0.83 images per day in the standard setting compared to control (P=.23) and increased by 1.78 images per day in the tailored setting compared to control (P≤.001). We found that 13/21 (62%) of participants preferred to use the image-based dietary record versus the text-based dietary record but reported method-specific challenges with each method, particularly the inability to record via an image after a meal had been consumed. Conclusions: Tailored prompting improves adherence to image-based dietary assessment. Future image-based dietary assessment tools should use tailored prompting and offer both image-based and written input options to improve record completeness.

Does diabetes affect breast cancer survival?

OBJECTIVES: The objective of this study is to investigate the influence of diabetes on breast cancer-specific survival among women with breast cancer in Aotearoa/New Zealand. METHODS: This study included women diagnosed with invasive breast cancer between 2005 and 2020, with their information documented in the Te Rehita Mate Utaetae-Breast Cancer Foundation National Register. Breast cancer survival curves for women with diabetes and those without diabetes were generated using the Kaplan-Meier method. The hazard ratio (HR) of breast cancer-specific mortality for women with diabetes compared to women without diabetes was estimated using the Cox proportional hazards model. RESULTS: For women with diabetes, the 5-year and 10-year of cancer-specific survival were 87% (95% CI: 85%-88%) and 79% (95% CI: 76%-81%) compared to 89% (95% CI: 89%-90%) and 84% (95% CI: 83%-85%) for women without diabetes. The HR of cancer-specific mortality for patients with diabetes compared to those without diabetes was 0.99 (95% CI: 0.89-1.11) after adjustment for patient demographics, tumor characteristics, and treatments. Age at cancer diagnosis and cancer stage had the biggest impact on the survival difference between the two groups. When stratified by cancer stage, the cancer-specific mortality between the two groups was similar. CONCLUSIONS: While differences in survival have been identified for women with diabetes when compared to women without diabetes, these are attributable to age and the finding that women with diabetes tend to present with more advanced disease at diagnosis. We did not find any difference in survival between the two groups due to differences in treatment.

A high quality Aotearoa New Zealand dietary pattern adapting a Mediterranean diet for metabolic health: a feasibility study.

AIM: To assess the feasibility of a family-based dietary intervention study using a meal kit home delivery service, in people at risk of cardio-metabolic disease. METHODS: A 12-week dietary intervention feasibility study of adults (termed the index participants) at increased risk of metabolic and cardiovascular disease, enriched for Maori who are indigenous New Zealanders. The study sample also included the household/whanau members living with the index participant. All participants received a 12 week intervention using weekly home delivery of meal kits and groceries consistent with a Mediterranean dietary pattern. Outcomes were the metabolic syndrome severity score (MetSSS); feasibility and acceptability of the intervention; dietary intake; and other clinical and anthropometric measures. RESULTS: There were 29 index participants recruited and in addition, 50 household/whanau members took part in the feasibility study. The mean (SD) household/whanau size was 3.45 (1.4) people, and the mean (SD) number of people in each household/whanau who participated in the study was 2.84 (1.2). The feasibility of intervention to households/whanau was proven in this context. The mean (SD) change in MetSSS was 0.03 (0.33), N = 27, P = 0.69 and there was a statistically significant decrease in body weight of 1.37 kg (95% CI 0.11 to 2.62), p = 0.034. The food deliveries were well received, the dinner kits more so than the grocery items. CONCLUSION: It is feasible to recruit individuals and households/whanau to a family-based dietary intervention. Use of a meal kit home delivery service to provide food which is consistent with the intervention dietary pattern was well received. This feasibility study identified improvements to be made such as nutrition behaviour change support, more variety in food provided, more recipes, and better matching of food quantity to family size. TRIAL REGISTRATION: ANZCTR-ACTRN12621000856819p registered 2.JUN.2021 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382021&isReview=true.

He Rourou Whai Painga, an Aotearoa New Zealand dietary pattern for metabolic health and whanau wellbeing: protocol for a randomized controlled trial.

Background: Cardiometabolic diseases are highly prevalent in Aotearoa New Zealand. Dietary intake is a modifiable risk factor for such diseases and certain dietary patterns, specifically the Mediterranean diet (MedDiet), are associated with improved metabolic health. This study aims to test whether an intervention including a Mediterranean dietary pattern incorporating high quality New Zealand foods (NZMedDiet pattern) and behavior change science can improve the metabolic health of participants and their household/whanau. Methods and analysis: This is a multi-center, three-stage trial with two parallel group superiority randomized controlled trials (RCTs), and a longitudinal cohort study embedded within the trial design. The first RCT (RCT 1) is a comparison of the NZMedDiet pattern compared to usual diet for 12 weeks. The Behavior Change Wheel was used to select and implement strategies to support participant adherence to the NZMedDiet, such as web-based nutrition education on healthy shopping and cooking. The second (RCT 2) compares online social support to no online social support for 12 weeks, administered to participants immediately following RCT 1. The third stage is a longitudinal cohort study where all participants are followed from the beginning of their start of the active intervention for 12 months in total. The primary outcome measure for each stage is the metabolic syndrome severity score (MetSSS). The duration of enrolment is 12-15 months. The total recruitment target is 200 index participants and their household/whanau members who participate with them, and the primary analyses will be intention to treat on index participants. Discussion: The trial will test whether the NZMedDiet pattern and behavior change support improves the cardiometabolic health of people in Aotearoa New Zealand. Clinical trial registration: https://www.anzctr.org.au/Default.aspx, identifier ACTRN12622000906752 and https://www.isrctn.com/, identifier ISRCTN89011056 (Spirit 2).

Habitual Dietary Patterns, Nutrient Intakes, and Adherence to the Mediterranean Diet among New Zealand Adults: The NZ MED Cross-Sectional Study.

There is increasing evidence that adherence to a Mediterranean dietary pattern reduces the incidence of diet-related diseases. To date, the habitual dietary intake of New Zealand (NZ) adults has not been examined in relation to its alignment with a Mediterranean-style dietary pattern. This study aimed to define the habitual dietary patterns, nutrient intakes, and adherence to the Mediterranean Diet in a sample of 1012 NZ adults (86% female, mean age 48 ± 16 years) who had their diabetes risk defined by the Australian Type 2 Diabetes Risk Assessment Tool (AUSDRISK). Dietary intakes were collected using a validated semi-quantitative NZ food frequency questionnaire, and dietary patterns were identified using principal component analysis. Reported intakes from the FFQ were used in conjunction with the Mediterranean-Style Dietary Pattern Score (MSDPS) to determine adherence to a Mediterranean dietary pattern. Mixed linear models were used to analyze the association between dietary patterns and MSDPS with demographics, health factors, and nutrient intakes. Two distinct dietary patterns were identified: Discretionary (positive loadings on processed meat, meat/poultry, fast food, sweet drinks, and sugar, sweets, and baked good) and Guideline (positive loadings on vegetables, eggs/beans, and fruits). Adherence to dietary patterns and diet quality was associated with age and ethnicity. Dietary patterns were also associated with sex. Adherence to a Mediterranean dietary pattern defined by the MSDPS was low, indicating that a significant shift in food choices will be required if the Mediterranean Diet is to be adopted in the NZ population.

Equity of Cancer and Diabetes Co-Occurrence: A National Study With 44 Million Person-Years of Follow-Up.

PURPOSE: The co-occurrence of diabetes and cancer is becoming increasingly common, and this is likely to compound existing inequities in outcomes from both conditions within populations. METHODS: In this study, we investigate the co-occurrence of cancer and diabetes by ethnic groups in New Zealand. National-level diabetes and cancer data on nearly five million individuals over 44 million person-years were used to describe the rate of cancer in a national prevalent cohort of peoples with diabetes versus those without diabetes, by ethnic group (Maori, Pacific, South Asian, Other Asian, and European peoples). RESULTS: The rate of cancer was greater for those with diabetes regardless of ethnic group (age-adjusted rate ratios, Maori, 1.37; 95% CI, 1.33 to 1.42; Pacific, 1.35; 95% CI, 1.28 to 1.43; South Asian, 1.23; 95% CI, 1.12 to 1.36; Other Asian, 1.31; 95% CI, 1.21 to 1.43; European, 1.29; 95% CI, 1.27 to 1.31). Maori had the highest rate of diabetes and cancer co-occurrence. Rates of GI, endocrine, and obesity-related cancers comprised a bulk of the excess cancers occurring among Maori and Pacific peoples with diabetes. CONCLUSION: Our observations reinforce the need for the primordial prevention of risk factors that are shared between diabetes and cancer. Also, the commonality of diabetes and cancer co-occurrence, particularly for Maori, reinforces the need for a multidisciplinary, joined-up approach to the detection and care of both conditions. Given the disproportionate burden of diabetes and those cancers that share risk factors with diabetes, action in these areas is likely to reduce ethnic inequities in outcomes from both conditions.

A multiple case study of pre-diabetes care undertaken by general practice in Aotearoa/New Zealand: de-incentivised and de-prioritised work.

BACKGROUND: In Aotearoa/New Zealand (NZ) general practices diagnose and manage pre-diabetes. This work is important as it has the potential to delay or prevent the onset of Type 2 Diabetes (T2DM), reduce NZ's health inequities, and the burden that T2DM places on health care services. However, no study has previously examined how this work routinely occurs in NZ. METHODS: Two case studies of practices serving ethnically and socio-economically diverse populations, followed by cross-case analysis. RESULTS: The NZ health care context including funding mechanisms, reporting targets, and the disease centred focus of care, acted together to dis-incentivise and de-prioritise pre-diabetes care in general practices. The social determinants of health differentially influenced patients' ability to engage with and respond to pre-diabetes care, significantly impacting this work. Differing perspectives about the significance of pre-diabetes and gaps in systematic screening practices were identified. Interventions used were inconsistent and lacked comprehensive ongoing support. CONCLUSIONS: Complex multi-layered factors impact on pre-diabetes care, and many of the barriers cannot be addressed at the general practice level. The practice serving the most disadvantaged population who concurrently have higher rates of pre-diabetes/T2DM were more adversely affected by the barriers identified.

Impact of diabetes on surgery and radiotherapy for breast cancer.

PURPOSES: This study aims to examine whether diabetes has an impact on the use of surgery and adjuvant radiotherapy in treating women with localised breast cancer. METHODS: Women diagnosed with stage I-III breast cancer between 2005 and 2020 were identified from Te Rehita Mate Utaetae-Breast Cancer Foundation New Zealand National Register, with diabetes status determined using New Zealand's Virtual Diabetes Register. The cancer treatments examined included breast conserving surgery (BCS), mastectomy, breast reconstruction after mastectomy, and adjuvant radiotherapy after BCS. Logistic regression modelling was used to estimate the adjusted odds ratio (OR) and 95% confidence interval (95% CI) of having cancer treatment and treatment delay (> 31 days) for patients with diabetes at the time of cancer diagnosis compared to patients without diabetes. RESULTS: We identified 25,557 women diagnosed with stage I-III breast cancer in 2005-2020, including 2906 (11.4%) with diabetes. After adjustment for other factors, there was no significant difference overall in risk of women with diabetes having no surgery (OR 1.12, 95% CI 0.94-1.33), although for patients with stage I disease not having surgery was more likely (OR 1.45, 95% CI 1.05-2.00) in the diabetes group. Patients with diabetes were more likely to have their surgery delayed (adjusted OR of 1.16, 95% CI 1.05-1.27) and less likely to have reconstruction after mastectomy compared to the non-diabetes group-adjusted OR 0.54 (95% CI 0.35-0.84) for stage I cancer, 0.50 (95% CI 0.34-0.75) for stage II and 0.48 (95% CI 0.24-1.00) for stage III cancer. CONCLUSIONS: Diabetes is associated with a lower likelihood of receiving surgery and a greater delay to surgery. Women with diabetes are also less likely to have breast reconstruction after mastectomy. These differences need to be taken in to account when considering factors that may impact on the outcomes of women with diabetes especially for Maori, Pacific and Asian women.

Association of diabetes and breast cancer characteristics at diagnosis.

PURPOSE: This study aims to examine the association of diabetes and breast cancer characteristics at diagnosis in Aotearoa/New Zealand. METHODS: Patients diagnosed with invasive breast cancer between 2005 and 2020 were identified from the National Breast Cancer Register. Logistic regression modeling was used to estimate the adjusted odds ratio (OR) of having stage III-IV cancer and the OR of having stage IV cancer for women with diabetes compared to those without diabetes. The adjusted OR of having screen-detected breast cancers for patients aged 45-69 years with diabetes compared to patients without diabetes was estimated. RESULTS: 26,968 women were diagnosed with breast cancer, with 3,137 (11.6%) patients having diabetes at the time of cancer diagnosis. The probability of co-occurrence of diabetes and breast cancer increased with time. Maori, Pacific and Asian women were more likely to have diabetes than European/Others. The probability of having diabetes also increased with age. For patients with diabetes, the probability of being diagnosed with stage III-IV cancer and stage IV cancer was higher than for patients without diabetes (OR 1.14, 95% CI 1.03-1.27; and 1.17, 95% CI 1.00-1.38). Women aged 45-69 years with diabetes were more likely to have screen-detected cancer than those without diabetes (OR 1.13, 95% CI 1.02-1.26). CONCLUSIONS: The co-occurrence of diabetes and breast cancer is becoming more common. Overall there is a small but significant adverse impact of having advanced disease for women with diabetes that is found at the time of breast cancer diagnosis, and this may contribute to other inequities that occur in the treatment pathway that may impact on patient outcomes.

Cancer and diabetes co-occurrence: A national study with 44 million person-years of follow-up.

The number of new cases of cancer is increasing each year, and rates of diabetes mellitus are also increasing dramatically over time. It is not an unusual occurrence for an individual to have both cancer and diabetes at the same time, given they are both individually common, and that one condition can increase the risk of the other. In this manuscript, we use national-level diabetes (Virtual Diabetes Register) and cancer (New Zealand Cancer Registry) data on nearly five million individuals over 44 million person-years of follow-up to examine the occurrence of cancer amongst a national prevalent cohort of patients with diabetes. We completed this analysis separately by cancer for the 24 most commonly diagnosed cancers in Aotearoa New Zealand, and then compared the occurrence of cancer among those with diabetes to those without diabetes. We found that the rate of cancer was highest amongst those with diabetes for 21 of the 24 most common cancers diagnosed over our study period, with excess risk among those with diabetes ranging between 11% (non-Hodgkin's lymphoma) and 236% (liver cancer). The cancers with the greatest difference in incidence between those with diabetes and those without diabetes tended to be within the endocrine or gastrointestinal system, and/or had a strong relationship with obesity. However, in an absolute sense, due to the volume of breast, colorectal and lung cancers, prevention of the more modest excess cancer risk among those with diabetes (16%, 22% and 48%, respectively) would lead to a substantial overall reduction in the total burden of cancer in the population. Our findings reinforce the fact that diabetes prevention activities are also cancer prevention activities, and must therefore be prioritised and resourced in tandem.

They're sicker than we think: an exploratory study profiling the cardio-metabolic health in a sample of adults with pre-diabetes in Aotearoa New Zealand.

Introduction Type 2 diabetes mellitus (T2DM) is a highly prevalent and potentially preventable condition associated with significant health, social, and economic costs. The detection and management of pre-diabetes is an important opportunity to prevent or delay the onset of T2DM and associated morbidities; however, its importance is controversial as the health risks associated with pre-diabetes are poorly understood. Aim To understand the cardio-metabolic health profile of a sample of adults with pre-diabetes in Aotearoa New Zealand. Methods Secondary analyses of baseline data from all 153 adults recruited to an intervention trial for adults with pre-diabetes were carried out. A profile of cardio-metabolic risk was measured by describing the proportion with metabolic syndrome (MetS) calculated using Adult Treatment Panel III criteria, which includes blood pressure, lipids, and obesity in addition to glycaemic measures. The severity of MetS was calculated as MetS Z-scores. Subgroup analyses for sex, ethnicity and glycated haemoglobin (HbA1c ) were performed. Results Overall, 74% of this study population had MetS, and the proportion varied according to ethnicity and HbA1c level. The severity of MetS was highly variable, with MetS-Z-scores ranging from -1.0 to 2.8. Although mean MetS Z-scores differed according to ethnicity and HbA1c level, all subgroups included individuals with widely differing severity of MetS, suggesting likely quite different risks for progression to diabetes or cardiovascular disease across the range of pre-diabetes defined by HbA1c . Discussion Single biochemical markers of glycaemia are insufficient to ascertain overall cardio-metabolic risk when prioritising clinical efforts for those with pre-diabetes, particularly in primary care, where the potential for preventing or delaying the onset of type 2 diabetes mellitus (T2DM) is significant. Findings indicate the importance of attending to all cardio-metabolic risk factors when caring for people with pre-diabetes. The development of tools using multiple relevant variables and predicting a comprehensive range of outcomes would improve timely risk stratification and treatment effect monitoring of pre-diabetes populations.

Metabolic syndrome severity score (MetSSS) associates with metabolic health status in multi-ethnic Aotearoa New Zealand cohorts.

AIM: To investigate the relationship of metabolic syndrome severity score (MetSSS) with glucose regulatory and cardiovascular disease (CVD) status in Aotearoa New Zealand. METHODS: MetSSS and MetSSS component coefficients were calculated for participants from the cross-sectional Workforce Diabetes Study (WDS) (n = 5,806) and Diabetes, Heart and Health Survey (DHAH) (n = 4,010) and compared by ethnicity (European, Maori, Pacific and Asian), glucose regulatory status [impaired fasting glucose, impaired glucose tolerance and type 2 diabetes) and history of cardiovascular disease. RESULTS: MetSSS positively associated with impaired glucose regulatory status and history of cardiovascular disease for all ethnic groups. Ethnicity significantly affected different coefficients of the MetSSS components, however all ethnicities had an approximately normal MetSSS distribution, with Maori and Pacific curves being right-shifted compared to European. While the MetSSS thresholds that capture 80% of participant with type 2 diabetes (T2D) were higher for Maori and Pacific, the difference in MetSSS between those participants with and without type 2 diabetes within an ethnicity group was similar across ethnicities. CONCLUSION: MetSSS may have utility as a tool to quantify an individual's cardiometabolic disease risk within the multi-ethnic population of Aotearoa New Zealand, however ethnic-specific categories for disease risk are likely to be required.

Very low carbohydrate (ketogenic) diets in type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials.

AIM: Very low carbohydrate/ketogenic diets (VLC/KDs) are popular but their role in managing pre-diabetes and type 2 diabetes (T2D) is uncertain. This study uses a systematic review and meta-analysis of randomized controlled trials to estimate the effect of these diets in this population. MATERIALS AND METHODS: A systematic review identified randomized controlled trials of at least 6 months duration comparing efficacy and safety of VLC/KDs (≤50 g carbohydrate or ≤10% total energy from carbohydrate per day) with a control diet (carbohydrate above the VLC/KD threshold) in adults with pre-diabetes or T2D. The primary outcome variable was glycated haemoglobin (HbA1c) after 12 months. The meta-analysis method was inverse variance weighting of mean values for continuous variables. RESULTS: Key word searches identified 2290 studies; 2221 were not in scope. A full text review of 69 studies identified eight meeting inclusion criteria; in total, it involved 606 participants. Six studies reported HbA1c (%) at 12 months; four as change from baseline with a fixed effects estimate (95% confidence interval): VLC/KD minus control of 0.01% (-0.22 to 0.25), p = .91; and two as change from baseline: -0.65% (-0.99; -0.31) [-7.1 mmol/mol (-10.8; -3.4)], p < .001. Serum triglycerides were lower with VLC/KD versus control: -0.28 mmol/L (-0.44 to -0.11), p < .001. High-density lipoprotein was higher with an estimate of 0.04 mmol/L (0.01 to 0.08), p = .03, in the five studies reporting 12-month summary data. CONCLUSIONS: A VLC/KD may cause reductions in HbA1c and triglycerides in those with pre-diabetes or T2D but evidence of an advantage over other strategies is limited. More well-designed studies are required to provide certain evidence.

Uncertainty and certainty: perceptions and experiences of prediabetes in New Zealand primary care – a qualitative study.

Introduction Prediabetes is the asymptomatic precursor to type two diabetes mellitus, a significant and growing public health problem in New Zealand (NZ). Little is known about how general practitioners (GPs) and nurses view prediabetes care, and similarly little is known about how people with prediabetes view their condition and care. Aim This study aimed to investigate the views of NZ GPs and nurses, and people with prediabetes about prediabetes and its management. Methods This was a mixed qualitative methods study that is part of a randomised control trial of a prediabetes intervention. Results Three key themes emerged from the health professional data (GPs and nurses) and another three themes emerged from people with prediabetes data. GPs and nurses were uncertain about the progression of prediabetes; they felt prediabetes was not a priority and they were unsure about what to advise. People with prediabetes were uncertain about the diagnosis and information given to them; they were unsure about what to do about prediabetes and they found lifestyle change hard. Discussion GPs, nurses and people with prediabetes, expressed much uncertainty, but also some certainty about prediabetes. All were certain that prediabetes is common and increasing and that sustained lifestyle change was very difficult. But uncertainty prevailed about whether, in reality, prediabetes could be stopped, who would be most likely to benefit from lifestyle interventions and how best to achieve these. Older Maori and Pacific women were keen to promote lifestyle change and this appeared best done through Maori and Pacific peoples' organisations by means of co-designed interventions.

A randomised controlled trial of a probiotic and a prebiotic examining metabolic and mental health outcomes in adults with pre-diabetes.

AIMS: To evaluate the effect of the probiotic Lactobacillus rhamnosus HN001 and/or cereal enriched with oat-derived beta-glucan (OBG) on metabolic and mental health outcomes when administered to adults with pre-diabetes. DESIGN: 2×2 factorial design randomised, parallel-groups placebo-controlled; double-blinded for probiotic, single-blinded for cereals. PARTICIPANTS: Community-dwelling adults aged 18-80 years with pre-diabetes: glycated haemoglobin (HbA1c) 41-49 mmol/mol. INTERVENTIONS: Capsules containing Lactobacillus rhamnosus (HN001) (6×109 colony-forming units/day), or placebo capsules; and cereal containing 4 g/day OBG or calorie-matched control cereal, taken daily, for 6 months. Study groups were: (A) HN001 capsules+OBG cereal; (B) HN001 capsules+control cereal; (C) placebo capsules+OBG cereal and (D) placebo capsules+control cereal. OUTCOME MEASURES: Primary outcome: HbA1c at 6 months. SECONDARY OUTCOMES: fasting plasma glucose, fasting insulin, homeostatic model assessment of insulin resistance, fasting lipids, blood pressure, body weight, waist circumference, body mass index and mental well-being. RESULTS: 153 participants were randomised. There was complete HbA1c outcome data available for 129 participants. At 6 months the mean (SD) HbA1c was 45.9 (4.4) mmol/mol, n=66 for HN001, and 46.7 (4.3) mmol/mol, n=63 for placebo capsules; 46.5 (4.0) mmol/mol, n=67 for OBG and 46.0 (4.6) mmol/mol n=62 for control cereal. The estimated difference between HN001-placebo capsules was -0.83, 95% CI -1.93 to 0.27 mmol/mol, p=0.63, and between OBG-control cereals -0.17, 95% CI -1.28 to 0.94 mmol/mol, p=0.76. There was no significant interaction between treatments p=0.79. There were no differences between groups or significant interactions between treatments for any of the secondary outcomes. CONCLUSIONS: This study found no evidence of clinical benefit from the supplementation with either HN001 and/or cereal containing 4 g OBG on HbA1c and all secondary outcomes relevant to adults with pre-diabetes. TRIAL REGISTRATION NUMBER: Australian New Zealand Clincial Trials Registry number ACTRN12617000990325.

The minor allele of the CREBRF rs373863828 p.R457Q coding variant is associated with reduced levels of myostatin in males: Implications for body composition.

OBJECTIVE: The minor allele (A) of the rs373863828 variant (p.Arg457Gln) in CREBRF is restricted to indigenous peoples of the Pacific islands (including New Zealand Maori and peoples of Polynesia), with a frequency of up to 25% in these populations. This allele associates with a large increase in body mass index (BMI) but with significantly lower risk of type-2 diabetes (T2D). It remains unclear whether the increased BMI is driven by increased adiposity or by increased lean mass. METHODS: We undertook body composition analysis using DXA in 189 young men of Maori and Pacific descent living in Aotearoa New Zealand. Further investigation was carried out in two orthologous Arg458Gln knockin mouse models on FVB/NJ and C57BL/6j backgrounds. RESULTS: The rs373863828 A allele was associated with lower fat mass when adjusted for BMI (p < 0.05) and was associated with significantly lower circulating levels of the muscle inhibitory hormone myostatin (p < 0.05). Supporting the human data, significant reductions in adipose tissue mass were observed in the knockin mice. This was more significant in older mice in both backgrounds and appeared to be the result of reduced age-associated increases in fat mass. The older male knockin mice on C57BL/6j background also had increased grip strength (p < 0.01) and lower levels of myostatin (p < 0.05). CONCLUSION: Overall, these results prove that the rs373863828 A-allele is associated with a reduction of myostatin levels which likely contribute to an age-dependent lowering of fat mass, at least in males.

It is time for a more targeted approach to prediabetes in primary care in Aotearoa New Zealand.

Type 2 diabetes (T2DM), its related morbidities and entrenched diabetes-related inequities pose significant challenges for health care delivery systems in Aotearoa New Zealand (NZ). Primary care services undertake the majority of diabetes prevention work by initially detecting and managing those with prediabetes. In this viewpoint, we present available NZ data to highlight NZ trends in prediabetes and consider the current NZ clinical guidelines and the prediabetes care pathway. Multiple areas for improvement are identified to optimise diabetes prevention, potentially reduce T2DM inequities, and sustain more effective prediabetes management in primary care in NZ.