Increased risk of cardiovascular and renal disease, and diabetes for all women diagnosed with gestational diabetes mellitus in New Zealand-A national retrospective cohort study

BACKGROUND

Gestational diabetes mellitus increases the risk of developing type 2 diabetes. The aim of this study is to compare cardiometabolic and renal outcomes for all women in New Zealand with gestational diabetes (2001-2010) with women without diabetes, 10-20 years following delivery.

METHODS

A retrospective cohort study, utilizing a national dataset providing information for all women who gave birth between 1 January 2001 and 31 December 2010 (n = 604 398). Adolescent girls <15 years, women ≥50 years and women with prepregnancy diabetes were excluded. In total 11 459 women were diagnosed with gestational diabetes and 11 447 were matched (for age and year of delivery) with 57 235 unexposed (control) women. A national hospital dataset was used to compare primary outcomes until 31 May 2021.

RESULTS

After controlling for ethnicity, women with gestational diabetes were significantly more likely than control women to develop diabetes-adjusted hazard ratio (HR) 20.06 and 95% confidence interval (CI) 18.46-21.79; a first cardiovascular event 2.19 (1.86-2.58); renal disease 6.34 (5.35-7.51) and all-cause mortality 1.55 (1.31-1.83), all p values <.0001. The HR and 95% CI remained similar after controlling for significant covariates: diabetes 18.89 (17.36-20.56), cardiovascular events 1.79 (1.52-2.12), renal disease 5.42 (4.55-6.45), and all-cause mortality 1.44 (1.21-1.70). When time-dependent diabetes was added to the model, significance remained for cardiovascular events 1.33 (1.10-1.61), p = .003 and renal disease 2.33 (1.88-2.88), p < .0001 but not all-cause mortality.

CONCLUSIONS

Women diagnosed with gestational diabetes have an increased risk of adverse cardiometabolic and renal outcomes. Findings highlight the importance of follow-up screening for diabetes, cardiovascular risk factors, and renal disease.

Overview of results from the Vitamin D Assessment (ViDA) study

BACKGROUND

The Vitamin D Assessment (ViDA) study is a randomised, double-blind, placebo-controlled trial to evaluate the efficacy of monthly vitamin D supplementation in reducing the incidence of a range of acute and chronic diseases and intermediate outcomes.

METHODS

The study was carried out in Auckland, New Zealand, among 5110 adults, aged 50-84 years, who were followed for a median 3.3 years. The intervention was vitamin D3 (2.5 mg or 100,000 IU) or placebo softgel oral capsules, mailed monthly to participants' homes, with two capsules sent in the first mail-out post-randomisation (i.e. 200,000 IU bolus, or placebo), followed 1 month later (and thereafter monthly) with 100,000 IU vitamin D3 or placebo capsules. Outcomes were monitored through routinely collected health data and self-completed questionnaires.

RESULTS

The results showed no beneficial effect of vitamin D supplementation on incidence of cardiovascular disease, falls, non-vertebral fractures and all cancer. However, beneficial effects from vitamin D supplementation were seen: for persistence with taking statins in participants on long-term statin therapy; and also in bone mineral density and arterial function in participants with low 25-hydroxyvitamin D levels, and in lung function among ever smokers (especially if vitamin D deficient). The latter findings are consistent with several previous studies, CONCLUSION: Monthly high-dose vitamin D supplementation does not prevent a range of diseases, but may be beneficial for some intermediate outcomes in people who are vitamin D deficient.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry identifier: ACTRN12611000402943.

Trends in cardiovascular management of people with diabetes by primary healthcare nurses in Auckland, New Zealand

AIMS

The study aim was to re-examine current work practices and evaluate time trends in the cardiovascular management of people with diabetes consulted by primary healthcare nurses in New Zealand.

METHODS

Primary healthcare nurses in the Auckland region were surveyed in 2006-2008 and 2016, with about one-third of practice, home care and specialist nurses randomly selected to participate. Nurses completed a self-administered questionnaire about demographic and workplace details, and a telephone interview about clinical care provided for people with diabetes during nursing consultations. Information was collected on a representative sample of people with diabetes consulted on one randomly selected work-day in the previous week.

RESULTS

Of all people with diabetes consulted by nurses, practice nurses consulted significantly more in 2016 (83%) compared with 60% in 2006-2008, whereas specialist nurse consultations decreased from 23% to 8% (P = 0.01). In 2016, in people with diabetes, BMI was higher, and total cholesterol lower, yet the proportions of those receiving lifestyle advice (dietary and activity) remained unchanged from 2006-2008 levels. Smoking prevalence in people with diabetes was unchanged between the two surveys, although more people were asked if they wished to stop in 2016 compared with 2006-2008 (98% vs. 73%). In 2016, hours of nurses' diabetes education were associated with increased routine assessments of risk factors in people with diabetes and checking laboratory results.

CONCLUSIONS

Practice nurses are undertaking an increasing proportion of diabetes consultations. Although BMI in people with diabetes is increasing, the proportion of nurses offering lifestyle advice remains unchanged. Increasing diabetes education could strengthen the management of people with diabetes by community nurses.

Trends in the primary health care nursing workforce providing diabetes care in Auckland, New Zealand: A cross-sectional survey

AIMS

To describe trends from 2006-8 to 2016 in demographic, education and work settings of the primary health care nursing workforce who provide diabetes care in the Auckland region.

METHODS

A total of 1416 practice, Accident and Medical, district and diabetes specialist nurses were identified who provide community-based care. Of those, 459 were randomly selected and 336 were interviewed in 2016, and were compared with 287 nurses interviewed in 2006-8.

RESULTS

A 73% response rate was attained in 2016. Compared with nurses in 2006-8, primary health care nurses in 2016 were younger, less experienced, more likely to be Asian, undertook more post-graduate education, worked more in Accident and Medical Clinics and worked in larger practices with ≥4 doctors. However, less worked with a dietitian or received visits from specialist nurses compared with nurses in 2006-8. Significantly more nurses in 2016 had their own room for administrative work and the ability to email patients suggesting greater autonomy.

CONCLUSIONS

Major demographic, educational and workplace changes have occurred in the Auckland primary health care nursing workforce from 2006-8 to 2016. A significant increase in practice nurses and a large decrease in the number of diabetes specialist nurses were evident, in the Auckland region.

Pulse rate variability predicts atrial fibrillation and cerebrovascular events in a large, population-based cohort

BACKGROUND

Many patients with atrial fibrillation (AF) present with stroke as their first clinical manifestation and since improved AF screening methods are thus required, we investigated whether pulse rate variability parameters predict future AF and cerebrovascular events.

METHODS

In an observational cohort study of 5000 community-resident adults (58% male; 50-84 years), the beat-to-beat variability of suprasystolic brachial blood pressure waveforms was measured with root mean square of successive differences (RMSSD) and irregularity index (IrrIx). Based on outcome-oriented and previously validated thresholds for detecting AF, RMSSD and IrrIx were dichotomised at 100 ms and 7.7%, respectively. Participants were followed up for 4.6 years (median), accruing 249 AF and 120 cerebrovascular events in the total sample (n = 5000), and 133 AF and 90 cerebrovascular events among those without prior AF diagnosis (n = 4296).

RESULTS

In multivariable-adjusted analyses, an elevated RMSSD (>100 ms) or IrrIx (>7.7%) was strongly associated with a higher risk of AF (hazard ratios (HRs) = 2.00-2.95) and cerebrovascular events (HRs = 1.91-2.28), even among people without prior AF diagnosis: HRs for AF = 1.70-2.05 and cerebrovascular events = 2.00-2.28. These associations were strongest in the highest RMSSD tertile >100 ms or IrrIx tertile >7.7%: HRs for AF = 2.32-4.47 and cerebrovascular events = 2.43-3.69. Among those without prior AF diagnosis, the highest categorical net reclassification improvement for 5-year cerebrovascular risk was 14% (95% confidence interval: 7-21%).

CONCLUSIONS

Elevated RMSSD or IrrIx values indicative of the presence of AF predict future AF and cerebrovascular events; more so with increasing pulse irregularity and even among those without prior AF diagnosis.

Relations of Demographic and Clinical Factors With Cardiovascular Autonomic Function in a Population-Based Study: An Assessment By Quantile Regression

BACKGROUND

The relationships of many factors with cardiovascular autonomic function (CVAF) outcome parameters may not be uniform across the entire distribution of the outcome. We examined how demographic and clinical factors varied with different subgroups of CVAF parameters.

METHODS

Quantile regression was applied to a cross-sectional analysis of 4,167 adults (56% male; age range, 50-84 years) from 4 ethnic groups (3,419 New Zealand European, 303 Pacific, 227 Maori, and 218 South Asian) and without diagnosed cardiac arrhythmia. Pulse rate variability (root mean square of successive differences (RMSSD) and SD of pulse intervals) and baroreflex sensitivity were response variables. Independent variables were age, sex, ethnicity, brachial and aortic blood pressure (BP) variables, body mass index (BMI), and diabetes.

RESULTS

Ordinary linear regression showed that age, sex, Pacific and Maori ethnicity, BP variables, BMI, and diabetes were associated with CVAF parameters. But quantile regression revealed that, across CVAF percentiles, the slopes for these relationships: (i) varied by more than 10-fold in several cases and sometimes changed direction and (ii) noticeably differed in magnitude often (by >3-fold in several cases) compared to ordinary linear regression coefficients. For instance, age was inversely associated with RMSSD at the 10th percentile of this parameter (β = -0.12 ms/year, 95% confidence interval = -0.18 to -0.09 ms/year) but had a positive relationship at the 90th percentile (β = 3.17 ms/year, 95% confidence interval = 2.50 to 4.04 ms/year).

CONCLUSIONS

The relationships of demographic and clinical factors with CVAF parameters are, in many cases, not uniform. Quantile regression provides an improved assessment of these associations.

Sun exposure and 25-hydroxyvitamin D3 levels in a community sample: Quantifying the association with electronic dosimeters

There is uncertainty about the amount of sun exposure required to increase low blood 25-hydroxyvitamin D (25(OH)D₃) levels, a possible disease risk factor. The study aimed to quantify the association between sun exposure and serum 25(OH)D₃ concentrations in a multiethnic community sample (n=502) living in Auckland (37°S) and Dunedin (46°S), New Zealand, aged 18-85 years. They wore electronic ultraviolet dosimeters between March and November (autumn, winter and spring) for 8 weeks to record their sun exposure. This was converted to standard erythemal doses (SEDs), corrected for clothing to generate equivalent full-body exposures, SED_EFB. Blood samples were collected at the end of weeks 4 and 8 to measure 25(OH)D₃. Median weekly SED_EFB was 0.33 during weeks 1-4 and 0.34 during weeks 5-8. Weekly exposures <0.5 SED_EFB during weeks 5-8 were associated with decreasing 25(OH)D₃ concentrations at the end of week 8. There was a non-linear association between sun exposure and 25(OH)D₃, with most of the increase in 25(OH)D₃ being at exposures <2 SED_EFB per week. This finding suggests that vitamin D status is increased by regular small sun exposures (<2 SED_EFB per week), and that greater exposures result in only small additional increases in 25(OH)D₃.

Statin utilisation in a real-world setting: a retrospective analysis in relation to arterial and cardiovascular autonomic function

Randomized trials suggest that statin treatment may lower blood pressure and influence cardiovascular autonomic function (CVAF), but the impact of duration of usage, discontinuation, and adherence to this therapy is unknown. We examined these issues with regard to blood pressure (BP)-related variables in a large, population-based study. Participants were 4942 adults (58% male; aged 50-84 years): 2179 on statin treatment and 2763 untreated. Days of utilization, adherence (proportion of days covered ≥0.8), and discontinuation (non-use for ≥30 days immediately prior to BP measurement) of three statins (atorvastatin, pravastatin, and simvastatin) over a period of up to 2 years was monitored retrospectively from electronic databases. Systolic BP (SBP), diastolic BP (DBP), augmentation index, excess pressure, reservoir pressure, and CVAF (pulse rate and BP variability) parameters were calculated from aortic pressure waveforms derived from suprasystolic brachial measurement. Days of statin treatment had inverse relationships with pulse rate variability parameters in cardiac arrhythmic participants (20-25% lower than in statin non-users) and with most arterial function parameters in everyone. For example, compared to untreated participants, those treated for ≥659 days had 3.0 mmHg lower aortic SBP (P < 0.01). Discontinuation was associated with higher brachial DBP and aortic DBP (for both, β = 2.0 mmHg, P = 0.008). Compared to non-adherent statin users, adherent users had lower levels of brachial SBP, brachial DBP, aortic DBP, aortic SBP, and peak reservoir pressure (β = -1.4 to -2.6 mmHg). In conclusion, in a real-world setting, statin-therapy duration, non-discontinuation and adherence associate inversely with BP variables and, in cardiac arrhythmias, CVAF parameters.

Sun Exposure and Psychotic Experiences

OBJECTIVE

Sun exposure is considered the single most important source of vitamin D. Vitamin D deficiency has been suggested to play a role in the etiology of psychotic disorders. The aim of the present study was to evaluate the association between sun exposure and psychotic experiences (PEs) in a general population sample of Swedish women.

METHODS

The study population included participants from The Swedish Women's Lifestyle and Health cohort study. The 20-item community assessment of psychic experiences (CAPEs) was administered between ages 30 and 50 to establish PEs. Sun exposure as measured by (1) sunbathing holidays and (2) history of sunburn was measured between ages 10 and 39. The association between sun exposure and PEs was evaluated by quantile regression models.

RESULTS

34,297 women were included in the analysis. Women who reported no sunbathing holidays and 2 or more weeks of sunbathing holidays scored higher on the CAPE scale than women exposed to 1 week of sunbathing holidays across the entire distribution, when adjusting for age and education. Similarly, compared with women who reported a history of one sunburn, the women with none or two or more sunburns showed higher scores on the CAPE scale.

CONCLUSION

The results of the present study suggest that, in a population-based cohort of middle aged women, both low and high sun exposure is associated with increased level of positive PEs.

Different associations between beta-blockers and other antihypertensive medication combinations with brachial blood pressure and aortic waveform parameters

BACKGROUND

Comparing the relationships of antihypertensive medications with brachial blood pressure (BP) and aortic waveform parameters may help clinicians to predict the effect on the latter in brachial BP-based antihypertensive therapy. We aimed to make such comparisons with new waveform measures and a wider range of antihypertensive regimens than examined previously.

METHODS

Cross-sectional analysis of 2933 adults (61% male; aged 50-84years): 1637 on antihypertensive treatment and 1296 untreated hypertensives. Sixteen medicine regimens of up to 4 combinations of drugs from 6 antihypertensive classes were analysed. Aortic systolic BP, augmentation index (AIx), excess pressure integral (EPI), backward pressure amplitude (Pb), reflection index (RI) and pulse wave velocity (PWV) were calculated from aortic pressure waveforms derived from suprasystolic brachial measurement.

RESULTS

Forest plots of single-drug class comparisons across regimens with the same number of drugs (for between 1- and 3-drug regimens) revealed that AIx, Pb, RI and/or loge(EPI) were higher (maximum difference=5.6%, 2.2mmHg, 0.0192 and 0.13 loge(mmHg⋅s), respectively) with the use of a beta-blocker compared with vasodilators and diuretics, despite no brachial systolic and diastolic BP differences. These differences were reduced (by 34-57%) or eliminated after adjustment for heart rate, and similar effects occurred when controlling for systolic ejection period or diastolic duration.

CONCLUSIONS

Beta-blocker effects on brachial BP may overestimate effects on aortic waveform parameters. Compared to other antihypertensives, beta-blockers have weaker associations with wave reflection measures and EPI; this is predominantly due to influences on heart rate.

Factors associated with photoprotection by body clothing coverage, particularly in non-summer months, among a New Zealand community sample

Clothing coverage is important for reducing skin cancer risk, but may also influence vitamin D sufficiency, so associated plausible predictors require investigation. Volunteers (18 to 85 years), with approximately equal numbers by sex and four ethnicity groups, were recruited in cities from two latitude bands: Auckland (36.9°S) and Dunedin (45.9°S). Baseline questionnaire, anthropometric and spectrophotometer skin colour data were collected and weather data obtained. Percent body coverage was calculated from eight week diary records. Potential independent predictors (unadjusted p < 0.25) were included in adjusted models. Participants (n = 506: Auckland n = 334, Dunedin n = 172; mean age 48.4 years) were 62.7% female and had a median body clothing coverage of 81.6% (IQR 9.3%). Dunedin was cooler, less windy and had lower UVI levels than Auckland. From the fully adjusted model, increased coverage occurred in non-summer months (despite adjusting for weather), among Dunedin residents and Asians (compared to Europeans), during the middle of the day, with a dose response effect observed for greater age. Reduced coverage was associated with Pacific ethnicity and greater time spent outdoors. Additionally, higher temperatures were associated with reduced coverage, whereas increased cloud cover and wind speed were associated with increased coverage. Although the only potentially modifiable factors associated with clothing coverage were the time period and time spent outdoors, knowledge of these and other associated factors is useful for the framing and targeting of health promotion messages to potentially influence clothing coverage, facilitate erythema avoidance and maintain vitamin D sufficiency.

Light to moderate alcohol consumption is protective for type 2 diabetes mellitus in normal weight and overweight individuals but not the obese

OBJECTIVE

To examine the association between alcohol consumption and risk of type 2 diabetes mellitus (T2DM) overall and by body mass index.

METHODS

Cross-sectional study of employed individuals. Daily alcohol intakes were calculated from a self-administered food frequency questionnaire by 5,512 Maori, Pacific Island, and European workers (3,992 men, 1520 women) aged 40 years and above.

RESULTS

There were 170 new cases of T2DM. Compared to the group with no alcohol consumption and adjusting for age, sex, and ethnicity, the group consuming alcohol had relative risks of T2DM of 0.23 (95% CI: 0.08, 0.65) in normal weight individuals, 0.38 (0.18, 0.81) in overweight individuals, and 0.99 (0.59, 1.67) in obese individuals. After further adjusting for total cholesterol, HDL-cholesterol, triglycerides, smoking habit, physical activity, socioeconomic status, body mass index, and hypertension, the relative risks of T2DM were 0.16 (0.05, 0.50) in normal weight individuals, 0.43 (0.19, 0.97) in overweight individuals, and 0.92 (0.52, 1.60) in overweight individuals. Across the categories of alcohol consumption, there was an approximate U-shaped relationship for new cases of T2DM. There was no significant association between alcohol consumption and IGT.

CONCLUSIONS

Alcohol consumption was protective against diagnosis of T2DM in normal and overweight individuals but not in the obese.

Sizing the association between lifestyle behaviours and fatness in a large, heterogeneous sample of youth of multiple ethnicities from 4 countries

Background

The magnitude of the relationship between lifestyle risk factors for obesity and adiposity is not clear. The aim of this study was to clarify this in order to determine the level of importance of lifestyle factors in obesity aetiology.

Methods

A cross-sectional analysis was carried out on data on youth who were not trying to change weight (n = 5714), aged 12 to 22 years and from 8 ethnic groups living in New Zealand, Australia, Fiji and Tonga. Demographic and lifestyle data were measured by questionnaires. Fatness was measured by body mass index (BMI), BMI z-score and bioimpedance analysis, which was used to estimate percent body fat and total fat mass (TFM). Associations between lifestyle and body composition variables were examined using linear regression and forest plots.

Results

TV watching was positively related to fatness in a dose-dependent manner. Strong, dose-dependent associations were observed between fatness and soft drink consumption (positive relationship), breakfast consumption (inverse relationship) and after-school physical activity (inverse relationship). Breakfast consumption-fatness associations varied in size across ethnic groups. Lifestyle risk factors for obesity were associated with percentage differences in body composition variables that were greatest for TFM and smallest for BMI.

Conclusions

Lifestyle factors were most strongly related to TFM, which suggests that studies that use BMI alone to quantify fatness underestimate the full effect of lifestyle on adiposity. This study clarifies the size of lifestyle-fatness relationships observed in previous studies.

Dietary intakes of Pacific, Māori, Asian and European adolescents: the Auckland High School Heart Survey

OBJECTIVE

To compare dietary intakes of European, Māori, Pacific Island and Asian adolescents living in Auckland.

METHODS

A self-administered food frequency questionnaire was used to assess daily nutrient intakes of 2,549 14- to 21-year-old high-school students in Auckland (1,422 male and 1,127 female) in a cross-sectional survey carried out between 1997 and 1998.

RESULTS

Compared with Europeans, Māori and Pacific Islanders consumed more energy per day. Carbohydrate, protein and fat intakes were higher in Māori and Pacific Islanders than in Europeans. Cholesterol intakes were lowest in Europeans and alcohol intakes were highest in Europeans and Māori. When nutrient intakes were expressed as their percentage contribution to total energy, many ethnic differences in nutrient intakes between Europeans and Māori or Pacific Islanders were eliminated. After adjustment for energy intake and age, Europeans ate the fewest eggs, and Pacific Islanders and Asians ate more servings of chicken and fish, and fewer servings of milk and cereal than Europeans. Compared to Europeans, Pacific Islanders consumed larger portion sizes for nearly every food item.

CONCLUSION

There were marked differences in nutrient intakes between Pacific, Māori, Asian and European adolescents. Ethnic differences in food selections, frequency of food servings and portion sizes contribute to the differences in nutrient intakes between these ethnic groups. These differences generally matched those of other studies in children and adults from these ethnic groups.

IMPLICATIONS

Interventions that reduce frequency of food consumption and serving sizes and promote less-fatty food choices in Māori and Pacific adolescents are needed.

Body mass index and percent body fat in a New Zealand multi-ethnic adolescent population

Abstract Objective. Previous studies show that body mass index (BMI) does not fully explain differences in percent body fat (%BF) between ethnic groups and few studies have investigated this in adolescents. We sought to compare %BF for a given BMI between adolescents from four ethnic groups and to explain ethnic differences in this relationship. Methods. Weight, height and waist circumference were measured in 202 boys and 197 girls (age range 12-19 years; 129 Pacific Island, 91 European, 90 Maori and 89 Asian Indian). Fat mass, appendicular skeletal muscle mass (ASMM), leg length, bone mineral content (BMC), and fat distribution measures were derived from dual-energy X-ray absorptiometry. Results. For the same BMI and age, compared with European boys, %BF in Maori, Pacific Island and Asian Indian boys was 2.8% lower (P=0.017), 5.2% lower (P<0.0001), and 3.5% higher (P=0.0025), respectively. Compared with European girls, %BF, adjusted for BMI, for Maori, Pacific Island and Asian Indian girls was 1.9% lower (P=0.024), 4.1% lower (P<0.0001) and 3.6% higher (P<0.0001), respectively. Adjustment for ASMM, BMC and fat distribution variables, in particular, significantly reduced the differences between ethnic groups. In boys, readily measured variables, conicity index and waist circumference/height, had notable effects on ethnic differences in %BF. Conclusions. Our results show that BMI is not an equivalent measure of %BF between adolescent Europeans, Maori, Pacific Islanders and Asian Indians. Differences in muscularity, bone mass, relative leg length, fat distribution and body shape contribute to this disparity.

Prediction of fatness by standing 8-electrode bioimpedance: a multiethnic adolescent population

The objective of this study was to validate an 8-electrode bioimpedance analysis (BIA(8)) device (BC-418; Tanita, Tokyo, Japan) for use in populations of European, Maori, Pacific Island, and Asian adolescents. Healthy adolescents (215 M, 216 F; 129 Pacific Island, 120 Asian, 91 Maori, and 91 European; age range 12-19 years) were recruited by purposive sampling of high schools in Auckland, New Zealand. Weight, height, sitting height, leg length, waist circumference, and whole-body impedance were measured. Fat mass (FM) and fat-free mass (FFM) derived from the BIA(8) manufacturer's equations were compared with measurements by dual-energy X-ray absorptiometry (DXA). DXA-measured FFM was used as the reference to develop prediction equations based on impedance. A double cross-validation technique was applied. BIA(8) underestimated FM by 2.06 kg (P < 0.0001) and percent body fat (%BF) by 2.84% (P < 0.0001), on average. However, BIA(8) tended to overestimate FM and %BF in lean and underestimate FM and %BF in fat individuals. Sex-specific equations developed showed acceptable accuracy on cross-validation. In the total sample, the best prediction equations were, for boys: FFM (kg) = 0.607 height (cm)(2)/impedance ( ohm) + 1.542 age (y) + 0.220 height (cm) + 0.096 weight (kg) + 1.836 ethnicity (0 = European or Asian, 1 = Maori or Pacific) - 47.547, R(2) = 0.93, standard error of estimate (SEE) = 3.09 kg; and, for girls: FFM (kg) = 0.531 height (cm)(2)/impedance ( ohm) + 0.182 height (cm) + 0.096 weight (kg) + 1.562 ethnicity (0 = non-Pacific, 1 = Pacific) - 15.782, R(2) = 0.91, SEE = 2.19 kg. In conclusion, equations for fatness estimation using BIA(8) developed for our sample perform better than reliance on the manufacturer's estimates. The relationship between BIA and body composition in adolescents is ethnicity dependent.

Ethnic differences in cardiovascular disease risk factors and diabetes status for Pacific ethnic groups and Europeans in the Diabetes Heart and Health Survey (DHAH) 2002-2003, Auckland New Zealand

AIM

The aim of this paper is to provide levels of cardiovascular disease (CVD) risk factors and diabetes status for Pacific ethnic groups and make comparisons amongst these groups (Samoan, Tongan, Niuean, Cook Islanders) with European New Zealanders by gender from the 2002-03 DHAH Survey.

METHODS

The DHAH was a cross-sectional population-based survey and was carried out in Auckland between 2002-03. A total of 1011 Pacific comprising of 484 Samoan, 252 Tongan, 109 Niuean, 116 Cook Islanders, and 47 Other Pacific (mainly Fijian) and 1745 European participants took part in the survey. Participants answered a self-administered questionnaire to assess whether they had previously diagnosed CVD risk factors (blood pressure, cholesterol, diabetes) and lifestyle risk factors (smoking, physical inactivity). All participants provided an early morning mid-stream urine sample, an initial blood test and full glucose tolerance test (GTT) for those not previously diagnosed with diabetes.

RESULTS

In both men and women, CVD risk among the Pacific groups were all significantly higher than Europeans. Niueans had the lowest Pacific CVD risk and Samoans had the highest estimated risk. Individual risk factors differed between the groups, however; the most observable differences were the more adverse lipid profile in Tongan men and the lower total cholesterol and micro-albumin in Niuean women when compared to their Samoan counterparts. Diabetes prevalence was highest in Samoan men (26.2%) and Tongan women (35.8%). Tongan women had a diabetes prevalence over double that of their men (17.8%), whereas in the other Pacific groups, male and female prevalence was very similar. Niueans had the lowest diabetes prevalence of both sexes (men 14.9%, women 10.8%). Undiagnosed diabetes as a proportion of total diabetes was similar in Samoan, Niuean and Cook Islands groups (1/4-5) suggesting efficient screening. Cook Islanders had a ratio of one undetected diabetes case for every two known cases.

CONCLUSION

CVD risk factors, diabetes prevalence, and levels of undetected diabetes differed between the Pacific ethnic groups with Niueans having the healthiest profile. More rigorous screening of diabetes in Cook Islanders is needed if they are to experience similar detection rates as other Pacific Island communities in New Zealand. Greater attention is required to identify and manage CVD risk among all Pacific peoples to reduce the gap in CVD risk factors, morbidity and mortality when compared to European New Zealanders.

Comparison of three different methods of assessing cardiovascular disease risk in New Zealanders with Type 2 diabetes mellitus

AIM

To compare three methods of assessing 5-year absolute risk of cardiovascular disease (CVD) in adults with type 2 diabetes; the Framingham CVD equation, the UK Prospective Diabetes Study (UKPDS) coronary heart disease plus stroke equations and the New Zealand Guidelines Group (NZGG)-modified Framingham CVD equation.

METHODS

Participants were 423 people with newly (n=118) or previously diagnosed (n=305) Type 2 diabetes mellitus aged 35 to 74 years with no past history of cardiovascular disease or nephropathy from an interviewed study population of 4049 adults. Absolute 5-year CVD risks were calculated in 5-year age bands by gender; Maori, Pacific, and European ethnicity; and newly and previously diagnosed diabetes.

RESULTS

The mean 5-year CVD risk score was 2.9% (95%CI: 2.40-3.42; p<0.0001) lower for the UKPDS risk engine compared to the original Framingham equation in absolute terms, and 7.6% (95%CI: 7.05-8.08; p<0.0001) lower than the NZGG-modified Framingham equation. In general, 5-year CVD risks were highest using the NZGG-modified equation, intermediate using the original Framingham equation and lowest using the combined UKPDS coronary heart disease plus stroke equations, in all age groups by gender, ethnicity, and time of diagnosis of Type 2 diabetes. However, the 5-year CVD risks are themselves potentially low as they include treated blood pressure and lipid values. Compared to the UKPDS 15% level of risk, the NZ Guidelines modified 15% level of risk results in people with diabetes being recommended for CVD drug management 10 to 17 years earlier.

CONCLUSIONS

In general, among people with Type 2 diabetes, the Framingham equations showed higher 5-year CVD risk estimates compared to combined UKPDS coronary heart disease plus stroke equations and the NZGG-modified Framingham equation showed the highest 5-year CVD risks. In practice, people with type 2 diabetes will be managed earlier and more intensively based on their risk estimated by the current NZGG guidelines than if the UKPDS or original Framingham equations were used.

Design effects associated with dietary nutrient intakes from a clustered design of 1 to 14-year-old children

OBJECTIVE

To calculate intra-cluster and intra-household design effects and intra-class correlation coefficients for dietary nutrients obtained from a 24 h record-assisted recall.

DESIGN

Children were recruited using clustered probability sampling. Randomly selected starting-point addresses were obtained with probability proportional to mesh block size.

SETTING

Children aged 1-14 years in New Zealand.

SUBJECTS

There were 125 children in 50 clusters, giving an average of 2.498 children per cluster. In 15 homes, there were two children for the calculation of intra-household statistics.

RESULTS

Intra-cluster design effects ranged from 1.0 for cholesterol, beta-carotene, vitamin A, vitamin D, vitamin E, selenium, fructose and both carbohydrate and protein expressed as their contribution to total energy intakes to 1.552 for saturated fat, with a median design effect of 1.148. Their corresponding intra-cluster correlations ranged from 0 to 0.37, respectively. Intra-household design effects ranged from 1.0 for height to 1.839 for vitamin B(6), corresponding to intra-household correlations of 0 and 0.839. The median intra-household design effect was 1.550. Using a sampling design of two to three households per cluster for estimating dietary nutrient intakes would need, on average, a 15% increase in sample size compared with simple random sampling with a maximum increase of 55% to cover all nutrients.

CONCLUSIONS

These data enable sample sizes for dietary nutrients to be estimated for both cluster and non-cluster sampling for children aged 1-14 years. The larger design effects found within households suggest that little extra information may be obtained by sampling more than one child per household.

Long-term effects of a reduced fat diet intervention on cardiovascular disease risk factors in individuals with glucose intolerance

The long-term effects on cardiovascular disease risk factors of a reduced fat (RF), ad libitum diet were compared with usual diet (control, CD) in glucose intolerance individuals. Participants were 136 adults aged > or =40 years with 'glucose intolerance' (2h blood glucose 7-11.0 mmol/l) detected at a Diabetes Survey who completed at 1 year intervention study of reduced fat, ad libitum diet versus usual diet. They were re-assessed at 2, 3 and 5 years. Main outcome measures were blood pressure, serum concentrations of total cholesterol, HDL and LDL cholesterol, total cholesterol:HDL ratio, triglycerides and body weight. The reduced fat diet lowered total cholesterol (P<0.01), LDL cholesterol (P< or =0.05), total cholesterol:HDL ratio (P< or =0.05), body weight (P<0.01) and systolic blood pressure (P< or =0.05) initially and diastolic blood pressure (P<0.01) long-term. No significant changes occurred in HDL cholesterol or triglycerides. In the more compliant 50% of the intervention group, systolic and diastolic blood pressure levels and body weight were lower at 1, 2 and 3 years (P<0.05). It was concluded that a reduced fat ad libitum diet has short-term benefits for cholesterol, body weight and systolic blood pressure and long-term benefits for diastolic blood pressure without significantly effecting HDL cholesterol and triglycerides despite participants regaining their lost weight.

Short-term repeatability of a food frequency questionnaire in New Zealand children aged 1–14 y

OBJECTIVE

To evaluate the repeatability of a children's food frequency questionnaire (FFQ) by gender, ethnicity, and age group.

DESIGN

A 117-item FFQ asking about food intake patterns over the past 4 weeks was developed using food records from 428 children (204 boys and 224 girls) and the reproducibility on average 13 days apart was tested in 130 children (78 boys and 52 girls). Children were recruited using clustered probability sampling (n=103), and a convenience sample of 25 Maori children.

SETTING

Children aged 1-14 y from Auckland, Feilding and Shannon, New Zealand.

SUBJECTS

There were 71 Maori, 20 Pacific, and 39 Other children.

RESULTS

Spearman correlations between the two FFQs ranged from 0.50 for bread to 0.82 for fruit, with a median of 0.76 for spreads and nonmilk drinks, and Cronbach's coefficient alpha's ranged from 0.59 for bread to 0.92 for nonmilk drinks, with a median of 0.85 for mixed meat dishes. There were no significant differences between the two administrations, apart from reporting higher intakes of vegetables and snacks & sweets in the first FFQ. Correlation coefficients tended to be slightly higher in boys than in girls, and in Other ethnic groups compared to Maori and Pacific children. Correlations were slightly higher for the 1-4 y age group, intermediate in the 10-14 y age group, and lowest in the 5-9 y-old age group.

CONCLUSIONS

Overall, the FFQ described here shows similar or better repeatability in New Zealand children of all major ethnic groups compared to other child or adolescent FFQs.

Stress at Work: An Evaluation of Occupational Stressors as Reported by a Multicultural New Zealand Workforce

Occupational stress is a cause of considerable morbidity, but research on work stressors has comparatively neglected the moderating effects of gender, age, ethnicity, and occupation. A workforce of 5,467 European, Maori, Pacific Islander, and Asian employees, 40 years old or older, working for 41 companies, completed a questionnaire giving details of total stressors and subcategories of stressors. Relative risks were estimated using numbers above and below median scores. There were significant associations between increased stressors and the following [with category showing highest relative risk, and corresponding relative risk (95% confidence interval)]: male gender [job scope, 1.50(1.37,1.63)]; young age [rapport with management, 1.34(11.23,1.46)]; administrative goup [job pressure, 1.85(1.69,2.03)]; and a negative association with Pacific Islander ethnicity [rapport with management, 0.59(0.52,0.66)]. These findings indicate areas in a workforce to which stress-reduction interventions can be directed.