Heart disease and diabetes risk factors in Pacific Islands communities and associations with measures of body fat.

AIMS: To describe the prevalence of obesity and other coronary heart disease and Type 2 diabetes risk factors by age and ethnic group in Pacific Island communities and to determine the associations between these risk factors and body mass index. METHODS: Cross-sectional data from commuity-based intervention projects were combined to provide anthropometric, blood sample and blood pressure data on 1,175 Pacific Islands people (467 men, 708 women) aged 20 years and over from church communities in South, Central and West Auckland. Self-reported data on diabetes status and leisure-time physical activity were also collected. RESULTS: Based on an ethnic-specific mass index (BMI) cut-off (> 32 kg/m2), 45% of men and 66% of women were obese. The age-standardised prevalence of known diabetes was 12%. Men and women aged 40-60 years had the highest risk factor levels and were the most sedentary. Tongans had higher risk factor levels than Samoans. In men, BMI and waist circumference were associated (p<0.05), in the direction of greater disease risk, with blood pressure and concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and blood glucose. In women, these associations were similar but less consistent. CONCLUSIONS: While these data are not representative for all Pacific people living in New Zealand, they do show an extremely high prevalence of obesity and significant associations between obesity and other cardiovascular risk factors. These communities warrant a very high priority as part of public health efforts to address New Zealand's growing obesity epidemic.     

Has the process causing noninsulin dependent diabetes start at birth? Evidence in neonates from a population with a high prevalence of diabetes.

AIMS: to investigate whether differences in the glucose-insulin axis are present at birth in neonates from ethnic groups at high risk of diabetes. METHODS: fructosamine samples were taken from Maori, European and Pacific Island expectant mothers at their 28 week appointment at the public outpatients clinic at National Women's Hospital, Auckland. Umbilical cord samples for insulin, C-peptide and fructosamine assay were taken at delivery and babies had their subscapular skinfold fat thickness measured by callipers. RESULTS: the mean maternal 28 week fructosamine was similar in the three populations in spite of a higher prevalence of gestational diabetes among Pacific Islanders. Of the 1066 deliveries, cord samples were available for 207 Europeans, 81 Maoris and 113 Pacific Islanders. Both Pacific Island and Maori babies had higher cord fructosamine concentrations than European babies. However, Pacific Island babies were also heavier, and had higher cord insulin concentrations and subscapular skinfold thickness than European babies. CONCLUSIONS: the elevated cord fructosamine concentrations suggest that Maori and Pacific Island babies, who share a high risk of noninsulin dependent diabetes mellitus later in life, are hyperglycaemic at birth. The paradoxical insulin results and the cause for the relative neonatal hyperglycemia warrant further investigation.     

Prevalence of diabetes mellitus and impaired glucose tolerance in a New Zealand multiracial workforce

A cross sectional survey was carried out among a multiracial workforce of 5677 staff aged 40 to 64 years at worksites in Auckland and Tokoroa to determine the prevalence of diabetes mellitus and impaired glucose tolerance (IGT). The prevalences of diabetes mellitus and IGT were both similar for men and women, but increased with age. The relative risks for diabetes mellitus and for IGT were both inversely associated with gross annual household income, independent of age and ethnicity, being 1.61 (95% Cl = 1.10, 2.37) and 1.80 (95% Cl = 1.21, 2.67) respectively, in the lowest income group (less than $30,000) compared with the highest (greater than $40,000). Compared with Europeans, the relative risk of diabetes mellitus was significantly increased among Maori (3.63; 95% Cl = 2.48, 5.32), Pacific Islanders (2.34; 95% Cl = 1.50, 3.66) and Asians (5.97; 95% Cl = 2.61, 13.65), after controlling for age, income and body mass index. The increased prevalence of diabetes mellitus among Maori and Pacific Islanders, but not in Asians, could be partly attributed to their increased levels of obesity compared with Europeans. However, other factors, in addition to obesity, explain the increased diabetes prevalence in nonEuropean groups.     

Progress of impaired glucose tolerance to diabetes mellitus among Niueans

Noninsulin dependent diabetes mellitus (NIDDM) is a major public health problem among Polynesians in the South Pacific. The prevalence of NIDDM on Niue Island is higher than other Pacific Islands and is increasing. NIDDM is preceded by a state of impaired glucose tolerance in some cases. Progress to NIDDM is associated with certain factors that are modifiable. In 1980, the South Pacific Commission conducted a metabolic disease survey on Niue. Sixty-one people were diagnosed as having impaired glucose tolerance. In 1985, 48 of these people (all those still on the island) were reexamined. Demographic, biological and indicators of westernisation were recorded. Thirty-one percent (6% per year) had progressed to diabetes mellitus. This was higher than rates described elsewhere but comparable with the rates described among the Pima Indians. Younger age, skilled occupations, high socioeconomic status and higher overall modernity were associated with progression to NIDDM.     

Cardiovascular risk factors levels of Pacific people in a New Zealand multicultural workforce

AIMS: To compare cardiovascular risk factors among the major Pacific Island communities participating in a New Zealand multicultural workforce survey. METHOD: There were 650 employed Pacific Island participants (Samoan 357, Cook Islands 177, Tongan 71, Niuean 45), aged 40-65 years, who were interviewed in a work-based, cross-sectional survey. During an oral glucose tolerance test, blood samples were collected for determination of blood glucose and serum lipids. Participants provided information on smoking and leisure time physical activity. Blood pressure, weight and height were measured and body mass index calculated. Ten-year risk of cardiovascular disease was calculated using equations from the Framingham study. RESULTS: Among men, their ten-year risk of a cardiovascular event was similar for the four communities compared (range 11.5% to 13.2%). However, individual risk factors did vary between the ethnic groups with Cook Island men having significantly higher total cholesterol, blood pressure and urinary microalbumin than other Pacific Island ethnic groups, while Tongan men were more likely to smoke and had lower HDL levels than other groups. Among women, Samoan and Cook Island participants had significantly higher ten-year cardiovascular risk scores (5.7%) than Niuean (4.4%) and Tongan (3.7%), due primarily to elevated total cholesterol levels. CONCLUSION: Cardiovascular risk factor levels vary between Pacific Islands communities in New Zealand. Targeted interventions to specific Pacific communities may be more beneficial than the current homogeneous prevention strategy applied to all communities.     

Asthma symptoms, bronchial hyperresponsiveness and atopy in a Maori and European adolescent population

In 1989 a survey of 543 New Zealand rural adolescents of largely Maori descent was undertaken to determine the prevalence of asthma symptoms, bronchial hyperresponsiveness (BHR) and atopy. The overall prevalence of asthma was estimated at 13.7%, BHR at 13.4% and atopy at 31.1%. These rates were similar across the age range 13 to 18 years. The prevalence of BHR among those without asthma symptoms was 3%. Both current asthma symptoms and BHR were more common among females, but there was no difference between the sexes in the proportion with atopy. The prevalence of asthma symptoms was higher among Maoris than nonMaoris, but this difference disappeared when allowance was made for current smoking. There was a similar prevalence of BHR and atopy between these two ethnic groups. There was a similar prevalence of asthma but lower prevalence of BHR than was reported among 7-10 year olds in an urban Auckland survey. The low prevalence of BHR among those without asthma symptoms, and the uniform frequency of asthma symptoms, BHR and atopy over the age range suggest that adolescents would be a particularly useful population for national or international comparisons of the prevalence of asthma, BHR and atopy.     

Incidence of cancer among Pacific Island people in New Zealand.

AIM: to describe the epidemiology of new cancer registrations among Pacific Island people in New Zealand with a view to identifying important cancers for preventive activities. METHODS: new cancer cases registered with the New Zealand Cancer Registry of the Health Statistical Services for the decade 1979-88 were analysed. Cancer cases among Pacific Island people were compared with cancer cases among Maori and the remainder of the New Zealand population (other). RESULTS: while the number of cases reported among Pacific Island people was relatively small (1884), age standardised rates for cancer of all sites were much higher than age standardised rates for Maori and other populations. The age standardised rate (per 100,000 person years) for cancer of all sites among males in all age groups was 400 for Pacific Island, 308.8 for Maori and 295.3 for others. The age standardised rate for cancer of all sites among women in all age groups was 373.3 for Pacific Island women, 324.2 for Maori and 313.4 for other women. Liver cancer was more common among Pacific Island men than could be explained by temporary migration from the Pacific Islands for treatment. The age standardised rate for liver cancer was 28.2 for Pacific Island men, 11.4 for Maori and 1.9 for other men. Cancer of the cervix was the leading site among Pacific Island women as in Maori women, compared with breast cancer among women in the rest of the population. The age standardised rate for cervical cancer was 61.8 for Pacific Island, 69.0 for Maori and 59.3 for other women. CONCLUSION: in the decade 1979-88 there was an excess number of new registrations for some cancers described among Pacific Island people compared with Maori and other ethnic groups. Temporary migration from the Pacific Islands for treatment may explain some of the excess cases.     

Awareness of sudden infant death syndrome risk factors among mothers of Pacific infants in New Zealand

AIM: To describe the awareness of Sudden Infant Death Syndrome (SIDS) risk factors among mothers of Pacific infants in New Zealand. METHODS: The data were gathered as part of the Pacific Islands Families Study in which 1376 mothers were interviewed when their infants were six weeks old. Included in this interview were questions designed to examine the mothers' awareness of SIDS risk factors. RESULTS: Over one third (38.8%) of mothers were unable to accurately report a SIDS risk factor, 53.4% reported the risk associated with putting the baby to sleep in a prone position, 31.5% maternal smoking, and 19.5% correctly reported other SIDS risk factors. Lack of awareness of SIDS risk factors was significantly associated with Samoan and Cook Islands Maori ethnicity, being Pacific Islands born, having no post school qualifications, lower household income, not being fluent in English, having more than five children, and not attending antenatal classes. CONCLUSIONS: Despite SIDS prevention efforts, a considerable number of mothers in this cohort reported no awareness of SIDS risk factors. More effective methods are needed to provide consistent SIDS prevention information across Pacific ethnic groups.     

Sudden infant death syndrome among the Auckland Pacific communities 1988-1996: is it increasing?

AIMS: To define ethnic origin and verify the diagnosis of sudden infant deaths among Pacific peoples in Auckland 1988-1996, and to elicit soci-econonic and demographic characteristics. METHODS: Police (P47) and coroner reports were analysed for an ethnic classification and diagnosis. Postneonatal and sudden infant death syndrome (SIDS) register and New Zealand Information Services data were analysed for additional Pacific cases. Rates of Pacific SIDS in Auckland calculated. A Pacific SIDS database was developed and families were tracked. Face to face interviews covering the SIDS event were undertaken with selected families. Data were coded, stratified and a thematic approach to analysis was utilised. RESULTS: There were 52 cases of SIDS and the ethnic origins were: thirteen Samoans, nine Cook Islanders, seven Togans fifteen multiple ethnicity, and eight could not be verified. The annual rates of Pacific SIDS varied from less than one (in 1989) to 4.5 (in 1995) per 1000 Pacific live births. 34 cases (65%) couldd not be contacted and eighteen were traced. Nine in-epth interviews were conducted with caregivers of these cases. All babies had slept in the supine position, seven were breasted, and five of the mothers were non-smokers. Eight babies sept in the same room with their primary caregiver, with seven sleeping in their own bed. All of the mothers had had continuous access to childcare and support from their families, and seven had had previous children. Grief counselling for partners and children was identified as necessary by almost all the mothers. CNCLUSIONS: This preliminary study concludes that the rate of Pacific SIDS increased in 1995 and remains a serious problem. Ethnic misclassification and under reporting of SIDS cases is apparent among Pacific infants. There is a need to establish a national infant mortality database that collects accurate data incorporating standardised ethnic specific categories. Official routine and data sources also need to incorporate standardised ethnic specific categories. A national prospective study is required to study SIDS in Pacific communities as a basis for effective prevention strategies.     

Tuberculosis in New Zealand, 1985-90.

AIM: to examine recent trends in tuberculosis in New Zealand. METHODS: histologically and bacteriologically confirmed cases of tuberculosis notified to area health boards from 1985 to 1990 were analysed. RESULTS: a total of 843 cases were reported during 1985-90 for an average annual incidence rate of 4.2 cases per 100,000 population; incidence rates for each year were similar. The incidence of tuberculosis was higher among males than females and increased with age. Maori were five times more likely to develop tuberculosis than Europeans, Pacific Islanders were 10 times more likely, and persons of other ethnic groups combined were 15 times more likely. From 1985 to 1990, the number of cases decreased among Europeans, remained stable among Maori and Pacific Islanders, and increased among persons of other ethnic origin. CONCLUSION: although the overall incidence of tuberculosis is relatively low, it continues to be a public health problem in New Zealand, particularly among Maori and immigrants from Asia and the Pacific Islands.     

Community networking as a means for identifying people with diabetes in a rural, predominantly bicultural community in New Zealand

AIMS: To assess the use of community networking to estimate the prevalence of diabetes in a predominantly New Zealand Maori and European community. METHODS: A cross-sectional survey of people with known diabetes identified either through general practice or community networks (others with diabetes, public notices or public meetings) was undertaken. Ascertainment was compared using capture-recapture methods for two independent samples. RESULTS: Overall ascertainment by community networking was greater for Maori than Europeans (40 +/- 3% vs 15 +/- 2%, p < 0.001). Ascertainment using general practice registers was comparable in the two ethnic groups (48 +/- 4% vs 55 +/- 5%, respectively). Women were more likely than men to be contacted through community networking (odds ratio 1.47, 1.05-2.06). CONCLUSION: In closely knit communities, community networking provides an independent source for estimating the prevalence of diabetes.     

Prevalence of iron deficiency in Auckland high school students

AIMS: To determine the frequency of iron deficiency and anaemia in high school students. METHOD: The survey was carried out at eight Auckland high schools with a high proportion (> or =15%) of Pacific Islands students. All students in Forms 5-7 at these schools were invited to participate, and 1644 students (Pacific Island 765, Asian 350, European 295, Maori 234) had iron assessments (response rate 61%). Iron deficiency was defined as any two (or more) of the following, three: serum ferritin <12 microg/L, iron saturation <14%, or red cell distribution width >14.5%. Anaemia was defined as haemoglobin <120 g/L for females and <130 g/L for males. RESULTS: Iron deficiency and anaemia were each ten times more common in girls (18.3% and 11.5%, respectively) than boys (1.5% and 1.4%). In females, iron deficiency was two to three times more common in Maori (25.6%), Pacific Islanders (20.9%) and Asians (15.4%) compared with Europeans (8.3 %), while anaemia was three to four times more common in Asians (15.9%), Pacific Islanders (12.1%) and Maori (11.2%) compared with Europeans (4.2%). Iron deficiency and anaemia prevalences were inversely associated with aerobic fitness, but not with age or years since menarche. CONCLUSION: Prevalences of iron deficiency and anaemia are high in non-European female adolescents in Auckland, for reasons currently unknown.     

Salmonella typhi infection in adults is not limited to travellers returning from the tropics

We reviewed the case notes of 23 adult patients infected with Salmonella typhi and admitted to the infectious disease unit, Auckland Hospital between January 1977 and December 1984. Fifteen had typhoid fever and eight were chronic carriers of S typhi. All isolates were sensitive to amoxycillin, chloramphenicol and cotrimoxazole. Ten of those with typhoid fever had recently been in tropical countries, predominantly Pacific Islands. The remaining five all lived in South Auckland and had not travelled out of New Zealand: we suspect that contaminated shellfish collected from the Manukau Harbour in South Auckland were the source. Typhoid fever should be suspected in young travellers returning to New Zealand with fever, diarrhoea, abdominal pain and headache. Similarly this diagnosis should be suspected in Polynesians and Maoris from South Auckland who have not travelled. All but one patient with typhoid fever responded clinically to the initial regimen which was usually oral amoxycillin given for a median 18 days. One other patient relapsed. Cholescystectomy and subsequent oral antibacterials eradicated S typhi from five biliary carriers with abnormal gallbladders. Prolonged high dose oral amoxycillin alone was effective in one of two carrier patients with normal gallbladders. The role of the Department of Health in identifying carriers of S typhi remains important.     

Clinical and ethnic characteristics associated with urinary albumin excretion in noninsulin dependent diabetic subjects attending the Wellington Hospital diabetes clinic

In noninsulin dependent diabetes, elevation of urinary albumin excretion above the normal range is thought to predict increased mortality. A random urinary albumin/creatinine ratio and the following clinical characteristics were recorded on 405 patients with noninsulin dependent diabetes attending the Wellington Hospital diabetes clinic; (1) ethnic origin, (2) age, (3) sex, (4) age at diagnosis, (5) duration since diagnosis of diabetes, (6) body mass index, (7) systolic blood pressure, (8) diastolic blood pressure, (9) retinopathy, (10) insulin therapy, (11) antihypertensive therapy, and (12) the presence or absence of treated cardiovascular disease. The overall prevalence of elevated urinary albumin/creatinine ratio (greater than 2.2 mg/mmol) was 45%. Stepwise regression analysis showed that 12% of the variability of urinary albumin/creatinine ratio in our clinic population could be accounted for by ethnic origin of patients, with noncaucasians (the Maori, Pacific Islanders and Asians) having a higher urinary albumin excretion than caucasians (p less than 0.001). Systolic blood pressure, retinopathy and cardiovascular disease predicted a further 8% of this variability. The cause of this ethnic difference in urinary albumin excretion and its possible relationship to excess mortality in noncaucasians is not yet known.     

Genetic polymorphism of cytochrome P450 2C19 in healthy Malaysian subjects

AIMS: Impaired S-mephenytoin 4'-hydroxylation is a well-described genetic polymorphism affecting drug metabolism in humans. Although ethnic differences in its distribution of polymorphism has been described, it is not known whether there is an ethnic heterogeneity of the structure and expression of the CYP2C19 enzyme in the Malaysian population. METHODS: Study subjects were 142 healthy, unrelated Malaysians aged 18-29 years. Baseline omeprazole and 2-h postingestion omeprazole and 5'-hydroxyomeprazole concentrations were measured for CYP2C19 phenotype determination. Identification of CYP2C19 genotypes was performed with the use of polymerase chain reaction. RESULTS: Phenotyping of CYP2C19 revealed that the prevalence of poor metabolizers (PMs) in the Malaysian population was 14.1%, whereas prevalence of PMs in genotyping was 12.6%. The PM genotypic prevalence rate was 5.6% in Malays, 19.1% in Chinese and 10.0% in Indian subjects. There were significant differences in PM genotypic prevalence rates among the three primary ethnic groups (P < or = 0.05). CONCLUSIONS: Phenotyping and genotyping revealed significant differences in the prevalence rates among the three ethnic groups in Malaysia, with Chinese recording highest prevalence.     

Hospial admission among Pacific children Auckland 1992-97

AIMS: To describe the reasons for, and rates of, hospital admissions for Pacific children, compared with Maori and 'Other' (non Maori, non Pacific) children in Auckland over the six year period 1992 to 1997. METHOD: Analysis was carried out of the New Zealand National Health Information Service database for Auckland domiciled children to show diagnostic codes and hospital admission rates for 0-14 year old children, using the 1996 Census population as the denominator population. Age standardised rates were calculated using the 'Other' group of children as the standard population. RESULTS: All-cause admission rates were higher among Pacific Children, compared with Maori and 'Other' children. Pacific Children were over-represented in admissions for acute respiratory infections, pneumonia and asthma/chronic obstructive pulmonary diseases, compared with both Maori and 'Other' children. CONCLUSION: Pacific children had the highest hospital admission rates, the main reason being preventable respiratory tract conditions. These findings suggest that Pacific children should be a priority group for intervention at various levels. Improvements in socio-economic circumstances, access to early primary health care and community education supported by comprehensive ambulatory paediatric services (particularly with respect to respiratory conditions) need to be implemented urgently. Qualitative research is needed to determine why ethnic differences exist and to identify effective interventions for Pacific children.     

Iron deficiency anaemia and adverse dietary habits in hospitalised children.

AIMS: To determine the prevalence of iron deficiency anaemia in children hospitalised with acute illness and the frequency of adverse dietary habits in the children with iron deficiency anaemia. METHODS: This was a prospective study of all children, aged 9 to 23 months resident in metropolitan Auckland who were hospitalised at Starship Children's Hospital, from July to October 1997, with an acute medical illness and had a full blood count performed. Iron deficiency anaemia was defined as haemoglobin <110 g/L, red cell distribution width >14.5% and either serum ferritin <10 microg/L or transferrin saturation <10%. Ethnicity and dietary habits of the children were determined by interviewing parents. RESULTS: During the study period 284 children, aged 9 to 23 months were admitted, of whom 206 (73%) had a full blood count performed. Sixty (29%) of these 206 children had iron deficiency anaemia. A larger proportion of Pacific Islands (P) compared to Maori (M) or European children (E) had iron deficiency anaemia. (P vs M:43% vs 21%, p=0.01; P vs E:43% vs 14%, p<0.001; M vs E 21% vs 14%, P=0.27). Sixty-nine percent of the children with iron deficiency anaemia had a dietary factor (early introduction of cows milk, late introduction of meat or regular consumption of tea) likely to have contributed to their iron deficiency. CONCLUSIONS: Iron deficiency is prevalent in Auckland children aged 9 to 23 months, hospitalised with an acute illness. The prevalence varies with ethnicity. Adverse dietary habits are present in 69% of the children with iron deficiency anaemia.     

Incidence and clinical features of breast cancer in the Auckland region.

Data on all new breast cancer cases in the Auckland area during the nine years September 1976 to September 1985 were used to obtain epidemiological information on breast cancer in the Auckland region. Breast tumours were found in 2706 women (300 per year), yielding a lifetime risk of breast cancer of one in 15. No significant difference in breast cancer incidence was detected between European, Maori and Pacific Island Polynesian women. Confidence limits for incidence were wide in the later groups. Fifty-one percent of women presented with intermediate sized (2-5 cm) tumours, and most (66%) were node negative. Eleven percent had evidence of metastatic disease at presentation. When the relationships between race, tumour size, nodal status and metastases were examined, Pacific Island women more frequently presented with large tumours and metastases, whereas Maori women were more frequently node positive. Eighty-five percent of tumours were invasive ductal carcinomas, 55% grade II, 35% grade III, and 10% grade I. Sixty-seven percent of tumours were oestrogen receptor positive (ER+ve) and ER status was significantly related to age; the proportion of ER+ve tumours was greater in older women. Fifty-seven percent of tumours were progesterone receptor positive (PR+ve), and PR distribution was bimodal with age. These data from the Auckland region are similar to breast cancer figures from other western countries, with some ethnic differences in tumour size and frequency of metastatic disease at presentation.     

Antibiotic resistance in the cultivable plaque microbiota of children from different ethnic groups

The presence of ampicillin-, penicillin-, erythromycin- and tetracycline-resistant bacteria in the dental plaque of White, South Asian and Japanese children was investigated. There was a high prevalence of antibiotic-resistant bacteria in children from diverse ethnic groups. The median percentage of the cultivable plaque microbiota that was resistant to tetracycline was greater in South Asian (2.9%, range 0.1-17.5%) and Japanese (7.7%, range 1.3-56.2%) children than in White children (0.7%, range 0-5.6%), suggesting that ethnic differences exist in the oral load of tetracycline-resistant bacteria (P<0.01). Multiresistant bacteria were frequently isolated, with 42% of isolates exhibiting resistance to two or more antibiotics. This study has demonstrated that antibiotic-resistant bacteria can be readily isolated from the plaque microbiota of children from different ethnic groups.