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Biomedical subjects

R Scragg

Publications and source records attributed to R Scragg.

At least 19 recordsLinked to original sources
PubMed2006

25-Hydroxyvitamin D, insulin resistance, and kidney function in the Third National Health and Nutrition Examination Survey.

Previous research has reported reduced serum 25-hydroxyvitamin D levels in patients with chronic kidney disease (CKD), although the relationship between vitamin D status and insulin resistance (IR) in patients with CKD has not been examined in the general population. We examined the association that kidney function, based on glomerular filtration rate (eGFR) estimated from serum creatinine, has with serum levels of 25-hydroxyvitamin D and components of the metabolic syndrome among 14 679 participants in the Third National Health and Nutrition Examination Survey (NHANES III). In this analysis, adjusted mean serum 25-hydroxyvitamin D was significantly lower only in the participants with a severe (15-29 ml/min/1.73 m(2)) decrease in eGFR compared to those with normal kidney function (61.6 vs 73.3 nmol/l, P=0.0063). Serum 25-hydroxyvitamnin D (P=0.0018) and level of kidney function (P=0.0003) were inversely associated, independent of each other, with homeostasis model assessment of insulin resistance (HOMA-IR), adjusting for confounders. Participants with high 25-hydroxyvitamin D levels (>81 nmol/l) had lower HOMA-IR. We conclude that 25-hydroxyvitamin D deficiency is not as prevalent in the US general population with decreased eGFR as previously reported in patients with CKD; and that vitamin D and kidney function have independent inverse associations with IR.

Adult↗
PubMed2005

Under-notification of giardiasis in Auckland, New Zealand: a capture-recapture estimation.

Estimation of the degree of undercount is important for disease surveillance. Capture-recapture techniques are now being used to evaluate the completeness of disease ascertainment. This study estimated the level of under-notification of giardiasis in the Auckland adult population using a capture-recapture method. Two independent datasets of giardiasis cases > or = 15 years were generated from the 1998-1999 Auckland Giardiasis Study (AGS) case database and cases notified to Auckland Regional Public Health Services (ARPHS) for the same period of time. Cases were matched and under-notification was estimated using a two-sample capture-recapture method. During the 12-month period, 199 cases participated in the AGS and 413 cases were notified to ARPHS. The capture-recapture calculation indicated that only 49% of cases were notified. Under-notification by a factor of 2 obscures the true burden of giardiasis. Socio-economic conditions and water quality may influence disease notification inversely. Capture-recapture techniques are useful in evaluating the completeness of surveillance.

Adolescent↗
PubMed2005

Randomized, double-blind comparison of growth in infants receiving goat milk formula versus cow milk infant formula.

OBJECTIVE: To compare growth of infants fed goat milk infant formula (GMF) or cow milk infant formula (CMF) and to compare tolerability and safety of the two formulas. METHODS: The study was conducted in Auckland, New Zealand. This was a double-blind randomized controlled trial. Newborn term infants were randomized within 72 h of birth to GMF or CMF. Milk formula powder in single serve sachets were reconstituted and fed to infants from trial commencement until age 168 days. No other formula given from randomization until age 168 days. Infant weight, length and head circumference were measured at birth and age 14, 28, 56, 84, 112, 140 and 168 days. Bowel motion frequency and consistency, sleeping and crying patterns and adverse events were also measured. RESULTS: Seventy-two infants were randomized, 36 each to GMF or CMF, with 62 infants completing the intervention. At enrollment the average weight of infants in the GMF group (mean +/- SD) was 3.33 +/- 0.43 kg and in the CMF group 3.43 +/- 0.47 kg; and at study completion 8.07 +/- 0.90 kg (GMF) and 7.87 +/- 0.99 kg (CMF). The difference in average weight gain over the study period for the GMF group versus the CMF group was not significant (+309 g; 95% CI = -49 to +668, P = 0.09). Median daily bowel motion frequency was greater in the GMF group than the CMF group (2.4 vs 1.7, P = 0.01). There were no group differences in bowel motion consistency, duration of crying, ease of settling, or frequency of adverse events. CONCLUSION: Growth of infants fed GMF is not different to that of infants-fed CMF.

Animals↗
PubMed2003

Children at risk of giardiasis in Auckland: a case-control analysis.

The incidence rate of giardiasis in New Zealand is one of the highest among developed countries, peaking in the 1-4 year age group. A case-control study was undertaken to identify risk factors for giardiasis among Auckland children under 5 years of age. The exposure history of 69 cases and 98 controls were analysed. Ninety-five per cent cases and 86% controls used water from the Auckland Metropolitan mains (AMM) supply for domestic purpose, 44 cases and 42 controls swam and 59 cases and 54 controls wore nappies. Children wearing nappies were at significantly increased risk of the disease (OR = 30, 95% CI = 1.01-8.9), as were those from households which had more than one child wearing a nappy (6.5, 1.8-23.4). The Auckland metropolitan mains water supply was associated with a reduced risk compared to other drinking water sources. Significantly increased risks were also associated with drinking water consumed away from home (4.7, 2.2-10.1), swimming at least once a week (2.4, 1.1-5.3) and travelling domestically (2.5, 1.03-6.0). The study identified vulnerable groups and modifiable risk factors for diarrhoeal diseases, particularly Giardia infection. Nappy wearing was an independent risk factor for infection. Further study is advocated to ensure better protection of public health, especially for children.

Case-Control Studies↗
PubMed2001

Nappy handling and risk of giardiasis.

We did a case-control study to identify modifiable risk factors for giardiasis in people aged 15-64 years living in Auckland, New Zealand. 183 patients with stool-positive Giardia spp referred to community laboratories were compared with 336 age-matched controls identified randomly from the Auckland telephone book. Exposure information for the previous 3 weeks was obtained retrospectively by telephone. Nappy changing was associated with a four-fold increased risk of infection after controlling for other confounders. We conclude that children wearing nappies could be an important source of giardia infection in the community.

Adolescent↗
PubMed2001

Ethnic comparisons of disease severity in children hospitalized with pneumonia in New Zealand.

OBJECTIVE: To determine if there are ethnic differences in disease severity in children hospitalized with pneumonia in New Zealand. METHODOLOGY: A population based audit of children hospitalized in Auckland with pneumonia over 12 months from 1 November 1994 to 31 October 1995. The study population was children aged from 0 to 14 years with a discharge diagnosis of pneumonia. The sample was stratified by ethnicity and included 151 Pacific, 85 Mäori and 151 European children. Measurements were made of demographics and prehospital care; vital signs and therapy received in the emergency department and inpatient wards and laboratory investigations performed. Comparisons between the three ethnic groups were adjusted for age, weight, gender, socio-economic status and relationship with primary care. RESULTS: A larger proportion of Pacific (15%) and Mäori (22%) children than European children (8%) had a respiratory rate elevated for > or = 2 days, odds ratio (OR) (95% CI): Pacific versus European 2.7 (1.1, 6.8), Mäori versus European 4.3 (1.7, 11.6). A larger proportion of Pacific (15%) and Mäori (15%) children than European children (< 1%) had a heart rate elevated for > or = 2 days, OR Pacific versus European 17.2 (3.2, 320), Mäori versus European 26.1 (4.4, 508). Compared with European children, a larger proportion of Pacific and Mäori children received intravenous fluids and antibiotics. A larger proportion of Pacific (29%) and Mäori (27%) children than European children (11%) received oxygen for > = 2 days, OR Pacific versus European 3.2 (1.6, 6.6), Mäori versus Europeans 2.6 (1.2, 6.2). CONCLUSIONS: Based on the comparisons of vital signs and intensity of therapy, Pacific and Mäori children hospitalized with pneumonia have more severe pneumonia than European children.

Adolescent↗
PubMed2001

Differences in disease frequency between Europeans and Polynesians: directions for future research into genetic risk factors.

The purpose of this review is to identify complex genetic diseases that might be common in Polynesian ethnic groups because of a high frequency of susceptibility genes. Since a number of Polynesian ethnic groups are descended from recent founder populations, they may be especially suitable for studies designed to identify these genes. We have reviewed the epidemiological literature looking for diseases that i) have a higher frequency in at least two Polynesian groups than in Europeans living in the same geographic areas, ii) are not at high frequency in Polynesia entirely because of high levels of known environmental risk factors, and iii) are known to be inherited in other ethnic groups. Twenty-one diseases fulfilling these three criteria were identified. It may be possible to design studies to identify the genes that cause these diseases in Polynesian ethnic groups.

Cardiovascular Diseases↗
PubMed2000

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.

Adolescent↗
PubMed2000

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.

Adult↗
PubMed1999

Changes in cigarette purchasing by fourth form students in New Zealand 1992-1997.

AIM: To determine recent changes in cigarette purchasing behaviour of 14- and 15-year-old students in New Zealand. METHOD: Nationwide cross-sectional surveys of fourth form students in 85 schools in New Zealand by means of an anonymous self-administered questionnaire collected in November 1992 and in November 1997. RESULTS: Analyses were restricted to 4198 out of 11 824 total students in 1992, and 4526 out of a total of 11 350 in 1997, who were current smokers aged 14 and 15 years. Self-purchasing of cigarettes decreased by 37% (95% CI: -40, -34) from 1992 to 1997, adjusting for age, sex and ethnicity, while acquiring cigarettes from other people increased. There was decreased purchasing from dairies (-6%; 95% CI: -8, -4) and supermarkets (-9%; 95% CI: -16, -1) but increases from other sources such as take-away shops, tobacconists and vending machines. From 1992 to 1997, weekly buying increased by 23% (95% CI 16, 32), students who were refused a sale increased by 153% (95% CI 139, 169) and students who had difficulty in buying increased by 324% (95% CI 276, 379). The latter were less likely to buy weekly than students who did not have difficulty (31.1% vs 41.4%). Students who smoked < or =5 cigarettes per week were 32% (95% CI 13, 53) more likely to have difficulty in buying than students smoking >20 per week. CONCLUSION: These results indicate major changes in cigarette purchasing behaviour between 1992 and 1997, when there was increased enforcement against underage sales of tobacco.

Adolescent↗
PubMed1999

Trends in cigarette smoking in fourth-form students in New Zealand, 1992-1997.

AIMS: To determine trends in the cigarette smoking behaviour of 14- and 15-year-old students in New Zealand. METHODS: Nationwide cross-sectional surveys of fourth-form students in New Zealand in 85 schools by anonymous self-administered questionnaire in 1992 and 1997. In 1992, 79% of schools and 70% of students responded; in 1997, 88% and 72%, respectively. RESULTS: Responses were analysed from 11,824 14- and 15 year-old fourth formers in 1992 and from 11,350 in 1997. Daily, weekly or monthly combined smoking prevalence increased by 27% (95% confidence interval (CI) 21-32), adjusting for age, sex and ethnicity, from 23.4% in 1992 to 28.5% in 1997. Daily smoking increased from 11.6% in 1992 to 15.5% in 1997 - an adjusted 37% (95% CI = 24-47) increase. The increase in daily smoking was: greater in girls (44%, 95% CI = 33-57) than boys (28%, 95% CI = 16-42), adjusting for age and ethnicity; unrelated to the socioeconomic decile of schools; and greatest in Auckland and Northland. CONCLUSION: This increase in smoking is large, 27-37% over five years, of uncertain cause, affects both sexes, all regions, ethnic and socio-economic groups, and certain cigarette brands. Regular school smoking surveys and more smokefree youth venues are recommended. Addiction and nicotine absorption merit monitoring. Legislation can require disclosure of manufacturing recipes used for youth-popular cigarette brands. On 1960-97 trends it would take 100 years to reduce fourth-form smoking to 5% prevalence. The proposed gradual denicotinisation of all cigarettes would allow smoking but prevent addiction, within ten years.

Adolescent↗
PubMed1999

Water fluoridation and the sudden infant death syndrome.

AIMS: To determine whether exposure to fluoridated water supplies prenatally or postnatally at the time of death increases the risk of sudden infant death syndrome (SIDS). METHODS: A nationwide, case-control study, with infant's water fluoridation status determined from census area unit information for mother's usual address at the time of the infant's birth, infant's usual address at the time of death / nominated sleep and address where infant died / was at nominated sleep. SIDS risk associated with fluoride exposure postnatally was assessed according to method of infant feeding (breast or reconstituted formula), for the two days prior to infant's death / nominated sleep. RESULTS: Infants exposed to fluoridated water supplies during pregnancy were not at increased risk for SIDS, adjusted odds ratio (OR) 1.19 (95% confidence interval (CI) 0.82, 1.74). For breast-fed infants at the time of death / nominated sleep, fluoridated water exposure was not associated with an increased risk for SIDS, adjusted OR 1.09 (95% CI 0.66, 1.79). Similarly, 'fluoridated' formula feeding, when compared with 'unfluoridated' formula feeding, showed no increased risk of SIDS, adjusted OR 1.25 (95% CI 0.73, 2.13). There was no evidence of an interaction between fluoridation and infant feeding for the last two days (chi2 = 0.171, df = 1, p = 0.68). CONCLUSION: Exposure to a fluoridated water supply prenatally or postnatally at the time of death did not affect the relative risk for SIDS.

Analysis of Variance↗
PubMed1999

The impact of modernisation on the diets of adults aged 20-40 years from Samoan church communities in Auckland.

The objective of this study was to describe the food and nutrient intakes of adults in three Samoan church communities located in Auckland, New Zealand. The study had a cross-sectional design and measured usual dietary intake in 437 participants, aged 20 years and over, using a self-completed, 89-item quantitative food frequency questionnaire. Median daily energy and nutrient intakes were calculated and compared by gender and age groups. Men obtained a significantly (p < 0.05) lower proportion of their energy from breads and cereals, fruits and vegetables and fats and oils than women. Compared to those aged 40+ years, those aged < 40 obtained a significantly (p < 0.01) lower proportion of their energy from meat, pulses and eggs, fruit and vegetables, and starchy staples. A significantly (p < 0.01) higher proportion of their energy intake came from takeaways, soft drinks, snacks and dairy products. Nutrient analysis revealed that those aged < 40 years obtained significantly (p < 0.001) more energy from fat and sugar, and less energy from protein (p < 0.001) than the older group. They also had significantly lower intakes, per 1000 kilocalories, of a wide selection of vitamins and minerals. A dietary transition has occurred for New Zealand Samoans, reflecting a shift from traditional to modern dietary patterns and a decline in the nutritional quality of the diet.

Adult↗
PubMed1998

Potential for prevention of premature death and disease in New Zealand.

AIM: To assess the potential for preventing major causes of premature death, disease and injury in New Zealand. METHODS: Population attributable risks for major modifiable risk factors for important causes of death and disease in New Zealand were calculated using available national and international data on the relative risk of disease and the prevalence of risk factors in the relevant New Zealand population. Attainable changes in risk factor prevalences were used to model population attributable risks over the next five years. These estimates were then used to estimate potential reductions in absolute numbers of deaths from major diseases. RESULTS: High population attributable risks were found for several disease/risk factor combinations: smoking and lung cancer (81% in Maori), smoking and coronary heart disease (44% in Maori), smoking and sudden infant death syndrome (49% in Maori); raised serum cholesterol and coronary heart disease (58%); physical inactivity and coronary heart disease (35%), physical inactivity and diabetes (30%), physical inactivity and colorectal cancer (33%), physical inactivity and fractured neck of femur (65%); obesity and hypertension (66%), obesity and diabetes (46%); lack of fruits and vegetables and stomach cancer (46%), and colorectal cancer (34%). The estimated, readily attainable reduction in absolute numbers of annual deaths due to decrease in risk factor prevalence was greatest for smoking (457 deaths), followed by hypertension (326), physical inactivity (303) and raised serum cholesterol (142). CONCLUSION: There is significant scope for reducing mortality from major non-communicable diseases although for some diseases such as the cancers, there will be a time lag of many years before the full benefits are realised. Together, reducing the prevalence of smoking, hypertension, physical inactivity and raised serum cholesterol would result in 1228 fewer deaths per year.

Exercise↗
PubMed1998

Hospitalization for pneumonia in children in Auckland, New Zealand.

OBJECTIVE: To describe the epidemiology of hospitalizations for pneumonia in children in Auckland, New Zealand. METHODS: A consecutive sample of children hospitalised with pneumonia at the Starship Childrens Hospital from 1 July 1993 to 30 June 1996. Subjects were Pacific Island, Maori, and European/other children aged 0-14 years resident in north, west and central Auckland who were hospitalized with pneumonia. Comparisons were made of the number of hospitalisations by year, ethnicity, age and season; and of the hospitalisation rates by year, ethnicity and age. RESULTS: There were 681 children who were hospitalized with pneumonia during 1993-94, 731 during 1994-95 and 630 during 1995-96. The average annual hospitalization rate was 5.0 per 1000 children aged 0-14 years (95% CI 4.8-5.2). The average annual hospitalisation rate for Pacific Island children was 14.0 per 1000 (95% CI 13.0-14.9), for Maori children 6.7 per 1000 (95% CI 6.0-7.4) and for European/other children was 2.7 per 1000 (95% CI 2.6-2.9). Fifty-three per cent of the hospitalised children were less than 2 years of age. A larger percentage of Pacific Island (61%) and Maori (60%) children were aged less than 2 years compared to European/other (42%) children (P < 0.001). There was marked seasonal variability in the number of hospitalizations, with peaks in hospitalizations corresponding to peaks in positive respiratory viral isolates. CONCLUSIONS: Pneumonia was a consistent cause of hospitalisation for a large number of Auckland children during this 3-year period. Hospitalisation rates and age distribution varied with ethnicity. Hospitalization rates were highest for Pacific Island. intermediate for Maori and lowest for European/other children. Based on these hospitalisation data, pneumonia is a significant cause of morbidity for children in Auckland, New Zealand.

Adolescent↗
PubMed1998

Heavy caffeine intake in pregnancy and sudden infant death syndrome. New Zealand Cot Death Study Group.

AIMS: To examine the association between maternal caffeine consumption during pregnancy and the risk of sudden infant death syndrome (SIDS). METHODS: A nationwide case-control study surveying parents of 393 SIDS victims and parents of 1592 control infants. Caffeine consumption in each of the first and third trimesters was estimated by questionnaire. Heavy caffeine intake was defined as 400 mg/day or more (equivalent to four or more cups of coffee per day). RESULTS: Infants whose mothers had heavy caffeine consumption throughout their pregnancy had a significantly increased risk for SIDS (odds ratio 1.65; 95% confidence interval 1.15 to 2.35) after adjusting for likely confounding factors. CONCLUSION: Caffeine intake has been associated with fetal harm and now SIDS. Reducing heavy caffeine intake during pregnancy could be another way to lessen the risk of SIDS. This needs confirmation by others.

Caffeine↗