Study Protocol – Metabolic syndrome, vitamin D and bone status in South Asian women living in Auckland, New Zealand: A randomised, placebo-controlled, double-blind vitamin D intervention

<p>Abstract</p> <p>Background</p> <p>The identification of the vitamin D receptor in the endocrine pancreas suggests a role for vitamin D in insulin secretion. There is also some limited evidence that vitamin D influences insulin resistance, and thus the early stages of the development of type 2 diabetes.</p> <p>Methods</p> <p>Eighty-four women of South Asian origin, living in Auckland, New Zealand, were randomised to receive either a supplement (4000IU 25(OH)D₃per day) or a placebo for 6 months. At baseline, all participants were vitamin D deficient (serum 25(OH)D₃<50 nmol/L), insulin resistant (HOMA-IR > 1.93) and/or hyperinsulinaemic, hyperglycemic or had clinical signs of dislipidaemia. Changes in HOMA-IR, lipids, parathyroid hormone, calcium and bone markers were monitored at 3 months and 6 months.</p> <p>Discussion</p> <p>This randomised, controlled trial will be the first to investigate the effect of vitamin D supplementation on insulin resistance in non-diabetic subjects. It will subsequently contribute to the growing body of evidence about the role of vitamin D in metabolic syndrome.Registered clinical.</p> <p>Trial registration</p> <p>Registered clinical trial – Registration No. ACTRN12607000642482</p

Associations of protein intake, sources and distribution on muscle strength in community-dwelling older adults living in Auckland, New Zealand

Protein intake, sources and distribution impact on muscle protein synthesis and muscle mass in older adults. However, it is less clear whether dietary protein influences muscle strength. Data were obtained from the Researching Eating Activity and Cognitive Health (REACH) study, a cross-sectional study aimed at investigating dietary patterns, cognitive function and metabolic syndrome in older adults aged 65–74 years. Dietary intake was assessed using a 4-d food record and muscle strength using a handgrip strength dynamometer. After adjusting for confounders, in female older adults (n 212), total protein intake (β = 0⋅22, P < 0⋅01); protein from dairy and eggs (β = 0⋅21, P = 0⋅03) and plant food sources (β = 0⋅60, P < 0⋅01); and frequently consuming at least 0⋅4 g/kg BW per meal (β = 0⋅08, P < 0⋅01) were associated with higher BMI-adjusted muscle strength. However, protein from meat and fish intake and the coefficient of variance of protein intake were not related to BMI-muscle strength in female older adults. No statistically significant associations were observed in male participants (n = 113). There may be sex differences when investigating associations between protein intake and muscle strength in older adults. Further research is needed to investigate these sex differences

A dose response study to assess the effects of New Zealand Pine Bark extract on glycaemic responses in healthy participants.

Background: The current estimation of 451 million people diagnosed with diabetes is expected to increase to 693 million by 2045. Plant extracts have been shown to improve glycaemic control in humans. However, evidence is lacking regarding the hypoglycaemic effects of New Zealand pine bark obtained from Pinus radiata trees

Effects of Greenshell™ mussel intervention on biomarkers of cartilage metabolism, inflammatory markers and joint symptoms in overweight/obese postmenopausal women: A randomized, double-blind, and placebo-controlled trial

ObjectiveTo investigate the effect of whole greenshell mussel (GSM) powder on biomarkers of cartilage metabolism, inflammatory cytokines, and joint symptoms in postmenopausal women with overweight/obesity and joint discomfort.DesignFifty-five postmenopausal women with overweight/obesity were randomly assigned to receive 3 g/day whole GSM powder or placebo for 12 weeks. Cartilage turnover biomarkers urinary C-telopeptide of type II collagen (CTX-II) and serum cartilage oligomeric matrix protein (COMP) were measured at baseline, week 6 and 12. Plasma cytokines were measured at baseline and week 12. Joint pain and knee-related problems were assessed at baseline and week 12 using a 100 mm Visual Analogue Scale (VAS) and the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, respectively.ResultsForty-nine participants completed the study (GSM n = 25, placebo n = 24). After 12 weeks, urinary CTX-II showed no significant change over time or between the groups (interaction effect P = 0.1). However, in women with symptomatic knees, a significant difference was noted between the group (treatment effect P = 0.04), as it was lower in the GSM group compared to placebo group at week 6 (P = 0.04) and week 12 (P = 0.03). Serum COMP and plasma cytokines were not affected. GSM supplementation showed greater reduction in the VAS pain score than placebo (−13.2 ± 20.3 vs. −2.9 ± 15.9; P = 0.04). No significant change in KOOS domains between the two groups was observed.ConclusionOral supplementation of whole GSM powder at 3 g/day may slow down the degradation of type II collagen in postmenopausal women with symptomatic knees. GSM treatment conferred clinical benefit on overall joint pain. No significant effect was noted for inflammatory cytokines, suggesting that GSM may act within the joint microenvironment rather than at the systemic level.Clinical trial registration[www.australianclinicaltrials.gov.au/clinical-trialregistries], identifier [ACTRN12620000413921p]

Dietary Patterns, Their Nutrients, and Associations with Socio-Demographic and Lifestyle Factors in Older New Zealand Adults

Dietary patterns analyse combinations of foods eaten. This cross-sectional study identified dietary patterns and their nutrients. Associations between dietary patterns and socio-demographic and lifestyle factors were examined in older New Zealand adults. Dietary data (109-item food frequency questionnaire) from the Researching Eating, Activity and Cognitive Health (REACH) study ( = 367, 36% male, mean age = 70 years) were collapsed into 57 food groups. Using principal component analysis, three dietary patterns explained 18% of the variation in diet. Dietary pattern associations with sex, age, employment, living situation, education, deprivation score, physical activity, alcohol, and smoking, along with energy-adjusted nutrient intakes, were investigated using regression analysis. Higher 'Mediterranean' dietary pattern scores were associated with being female, higher physical activity, and higher education ( <0.001, R = 0.07). Higher 'Western' pattern scores were associated with being male, higher alcohol intake, living with others, and secondary education ( <0.001, R = 0.16). Higher 'prudent' pattern scores were associated with higher physical activity and lower alcohol intake ( <0.001, R = 0.15). There were positive associations between beta-carotene equivalents, vitamin E, and folate and 'Mediterranean' dietary pattern scores ( <0.0001, R ≥ 0.26); energy intake and 'Western' scores ( <0.0001, R = 0.43); and fibre and carbohydrate and 'prudent' scores ( <0.0001, R ≥ 0.25). Socio-demographic and lifestyle factors were associated with dietary patterns. Understanding relationships between these characteristics and dietary patterns can assist in health promotion

Vitamin D and omega-3 fatty acid supplements in children with autism spectrum disorder: a study protocol for a factorial randomised, double-blind, placebo-controlled trial

Background: There is strong mechanistic evidence to suggest that vitamin D and omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs), specifically docosahexaenoic acid (DHA), have the potential to significantly improve the symptoms of autism spectrum disorder (ASD). However, there are no trials that have measured the effect of both vitamin D and n-3 LCPUFA supplementation on autism severity symptoms. The objective of this 2 × 2 factorial trial is to investigate the effect of vitamin D, n-3 LCPUFAs or a combination of both on core symptoms of ASD. Methods/design Children with ASD living in New Zealand (n = 168 children) will be randomised to one of four treatments daily: vitamin D (2000 IU), n-3 LCPUFAs (722 mg DHA), vitamin D (2000 IU) + n-3 LCPUFAs (722 mg DHA) or placebo for 12 months. All researchers, participants and their caregivers will be blinded until the data analysis is completed, and randomisation of the active/placebo capsules and allocation will be fully concealed from all mentioned parties. The primary outcome measures are the change in social-communicative functioning, sensory processing issues and problem behaviours between baseline and 12 months. A secondary outcome measure is the effect on gastrointestinal symptoms. Baseline data will be used to assess and correct basic nutritional deficiencies prior to treatment allocation. For safety measures, serum 25-hydroxyvitamin D 25(OH)D and calcium will be monitored at baseline, 6 and 12 months, and weekly compliance and gastrointestinal symptom diaries will be completed by caregivers throughout the study period. Discussion To our knowledge there are no randomised controlled trials assessing the effects of both vitamin D and DHA supplementation on core symptoms of ASD. If it is shown that either vitamin D, DHA or both are effective, the trial would reveal a non-invasive approach to managing ASD symptoms. Trial registration Australian New Zealand Clinical Trial Registry, ACTRN12615000144516. Registered on 16 February 2015. Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1428-8) contains supplementary material, which is available to authorized users

The role of vitamin D in metabolism and bone health : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Albany, New Zealand

Background Hypovitaminosis D is becoming recognised as an emerging threat to health, even in countries like New Zealand which enjoy plentiful sunshine. The evidence for a role for vitamin D deficiency in the aetiology of a plethora of diseases continues to accumulate, including type 2 diabetes, and the preceding insulin resistance. Objectives The primary objective of the Surya Study was to investigate the effect of improved vitamin D status (through supplementation) on insulin resistance. The secondary objectives were to investigate the vitamin D status and bone mineral density of South Asian women living in New Zealand, and to investigate the effect of vitamin D supplementation on bone turnover as measured by biochemical markers of bone resorption and formation. Method Women of South Asian origin, ≥20 years old, living in Auckland (n = 235) were recruited for the study. All were asked to complete a 4-day food diary, invited to have a bone scan, and were screened for entry into the intervention phase which required insulin resistance (HOMA-IR >1.93) and serum 25(OH)D < 50 nmol/L. Eighty-one completed a 6-month randomised controlled trial with 4000 IU vitamin D3 (n = 42) or placebo (n = 39). Primary endpoint measures included insulin resistance, insulin sensitivity (HOMA2%S), fasting C-peptide and markers of bone turnover, osteocalcin (OC) and collagen C-telopeptide (CTX). Ninety-one of the 239 had a bone scan and bone mineral density (BMD) was measured in the proximal femur and lumbar spine. Results Adequate serum 25(OH)D concentrations (>50 nmol/L) were observed in only 16% of subjects screened. Median (25th, 75th percentile) serum 25(OH)D increased significantly from 21 (11,40) to 75 (55,84) nmol/L with supplementation. Significant improvements were seen in insulin sensitivity and insulin resistance (P = 0·003, P = 0·02 respectively), and circulating serum insulin decreased (P = 0·02) with supplementation compared to placebo. There was no change in C-peptide with supplementation. Insulin resistance was most improved when endpoint serum 25(OH)D =80 nmol/L. In post-menopausal women OC and CTX levels increased in the placebo arm but CTX decreased from 0.39±0.15 to 0.36±0.17 (P = 0.012) with supplementation. Osteoporosis (T score <-2.5) was present in 32% of postmenopausal, and 3% of premenopausal women. Women 20 – 29 years (n=10) had very low BMD, calcium intake and serum 25(OH)D Conclusions Improving vitamin D status in insulin resistant women resulted in improved insulin resistance and sensitivity but no change in insulin secretion. Optimal 25(OH)D concentrations for reducing insulin resistance were shown to be ≥80 nmol/L. The prevalence of low 25(OH)D concentrations in this population was alarmingly high, especially in younger women. In post-menopausal women, vitamin D supplementation appeared to ameliorate increased bone turnover attributed to oestrogen deficiency

Factors Affecting 25-Hydroxyvitamin D Concentration in Response to Vitamin D Supplementation

Sun exposure is the main source of vitamin D. Due to many lifestyle risk factors vitamin D deficiency/insufficiency is becoming a worldwide health problem. Low 25(OH)D concentration is associated with adverse musculoskeletal and non-musculoskeletal health outcomes. Vitamin D supplementation is currently the best approach to treat deficiency and to maintain adequacy. In response to a given dose of vitamin D, the effect on 25(OH)D concentration differs between individuals, and it is imperative that factors affecting this response be identified. For this review, a comprehensive literature search was conducted to identify those factors and to explore their significance in relation to circulating 25(OH)D response to vitamin D supplementation. The effect of several demographic/biological factors such as baseline 25(OH)D, aging, body mass index(BMI)/body fat percentage, ethnicity, calcium intake, genetics, oestrogen use, dietary fat content and composition, and some diseases and medications has been addressed. Furthermore, strategies employed by researchers or health care providers (type, dose and duration of vitamin D supplementation) and environment (season) are other contributing factors. With the exception of baseline 25(OH)D, BMI/body fat percentage, dose and type of vitamin D, the relative importance of other factors and the mechanisms by which these factors may affect the response remains to be determined

Is waist circumference a useful indicator of markers of metabolic syndrome in South Asian women living in New Zealand?

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Combining food records with in‐depth probing interviews improves quality of dietary intake reporting in a group of South Asian women

Abstract Objective: To investigate if the addition of an in‐depth interview focused on cultural dietary practices could improve the quality of dietary data from food records among South Asian women in New Zealand. Methods: Cross‐sectional data were collected from 134 South Asian women (≥20 years), living in Auckland. Dietary data were collected using four‐day food records. Nutritional analysis revealed 33.6% under‐reporting of energy intakes. All women were recalled for an in‐depth probing interview focused on culture‐specific foods and dietary practices. Results: The interview revealed extensive use of dairy products and plant oils. The nutrient content of the food record alone and the food record plus interview were compared; median energy intakes were 6,852 kJ vs 7,246 kJ (p<0.001); under‐reporting decreased by 14.2%, and total fat and protein intakes (g/day) increased (p<0.001). Estimates of poly‐ and mono‐unsaturated fatty acids increased significantly (p<0.001) due to greater use of plant oils due to greater use of plant oils replacing saturated fatty acid‐rich fats in food preparation. A significant increase (17%) (p<0.001) in calcium intake reflects the higher dairy intake identified with the interview. Conclusion: The addition of an in‐depth probing interview to a four‐day food record enhanced food intake reporting. Self‐reported dietary assessments in immigrant population groups require quality control for accuracy. Implications: Methods to ensure high‐quality dietary data are essential to assess health outcomes and to inform public health interventions, especially in immigrant populations