PubMed Health⌕ Search

Biomedical subjects

I A Prior

Publications and source records attributed to I A Prior.

At least 19 recordsLinked to original sources
PubMed1989

Symptoms of asthma, methacholine airway responsiveness and atopy in migrant Tokelauan children.

503 migrant Tokelauan children between five and 15 years resident predominantly in Porirua and the Hutt Valley were surveyed as part of a study of asthma prevalence in a recently migrant population. The survey consisted of domiciliary interview with parents, physical examination, assessment of bronchial hyperresponsiveness and atopy, by allergen skin prick testing. Forty-three children (8%) had a history of wheezy breathing or asthma. 160 children (32%) had evidence of increased airway responsiveness defined as a PD20 (provocative dose of methacholine causing a less than or equal to 20% fall in FEV1, of less than or equal to 12.2 mumoL methacholine). Of the 43 children with a history of asthma, 40 (93%) had evidence of bronchial hyperresponsiveness, 36 (84%) were atopic and 35 (81%) had both bronchial hyperresponsiveness and atopy. Forty-five children (9%) were found to be wheezing on the day of examination only 16 of these had a history of wheezing. Twenty seven of the wheezing children demonstrated bronchial hyperresponsiveness and 22 of these were atopic. Of the 18 children wheezing but with no evidence of bronchial hyperresponsiveness only six were atopic. These contrasting findings suggest differences in the cause of symptoms among the children. Regional differences were observed for the prevalence of symptoms and signs of asthma, bronchial hyperresponsiveness and atopy. Hutt Valley Tokelauan children exhibited a higher prevalence than the Porirua children. Migrants to the Hutt Valley and Porirua are from different atolls, and these differences raise the possibility of a genetic influence on the development of asthma.

Adolescent↗
PubMed1989

Type 2 (non-insulin-dependent) diabetes mellitus, migration and westernisation: the Tokelau Island Migrant Study.

The migration of Tokelauans from a traditional atoll in the Pacific to urban New Zealand is associated with an increased prevalence and incidence of Type 2 (non-insulin-dependent) diabetes mellitus over the period 1968-1982. During the same period, a lesser but definite increase is seen among non-migrants in Tokelau. The age standardised prevalence rates rose from 7.5 and 11.7 to 10.8 and 19.9 per 100 respectively in the male and female migrants compared with an increase from 3.0 and 8.7 to 7.0 and 14.3 per 100 in the non-migrant males and females respectively. The incidence of diabetes is shown to be consistently higher in the migrants compared to the non-migrants giving relative risks of 1.5 in males and 1.9 in females. The factors most likely contributing to this difference, are changes to a higher calorie, high protein diet, higher alcohol consumption, a greater weight gain and altered levels of physical activity in the migrants. A number of populations in the Pacific have been shown to have a low rate of diabetes in their traditional setting, but may have a genetic predisposition for diabetes which responds to factors in the urban industrialised environment and life-style. The social and economic changes taking place in Tokelau are also clearly increasing the risk of diabetes. To reverse these trends and prevent the development of complications of Type 2 diabetes, it will be important to institute preventive programmes and to follow up the population in both environments for long-term outcomes, including mortality.

Adult↗
PubMed1989

The relationships between atopy, bronchial hyperresponsiveness, and a family history of asthma: a cross-sectional study of migrant Tokelauan children in New Zealand.

We have examined age-related changes in the association between nonspecific bronchial hyperresponsiveness (BHR) and atopy in 494 second-generation Polynesian migrant children, aged 5 to 15 years. BHR (provocative dose of methacholine, less than or equal to 7.8 mumol, causing a 20% fall in FEV1) was present in 125 children (25.3%). Atopy (skin wheal, greater than or equal to 4 mm diameter) was present in 157 children (32%). BHR associated with atopy demonstrated a constant age-related frequency in the 7- to 15-year-old children that was influenced by a family history (FH) of asthma (FH, 50%; no FH, 34%; p = 0.051). BHR not associated with atopy demonstrated a marked decreasing frequency with age from 25% in 5- to 7-year-old children to 3% in 13- to 15-year-old children and was uninfluenced by an FH of asthma. We conclude that the differences in the frequency of BHR with age, together with the genetic influence on BHR associated with atopy, compared with the findings in nonatopic children, indicate distinct heterogeneity in the pathogenesis of BHR in these Tokelauan children. These differences may be important for understanding the relationships between nonspecific BHR, atopy, and asthma in children.

Adolescent↗
PubMed1989

Blood pressure patterns and migration: a 14-year cohort study of adult Tokelauans.

The longitudinal relation between blood pressure changes and migration experience has been studied in a cohort of 654 adult Tokelauans through three survey periods between 1968 and 1982. Migration from a subsistence life-style on a Pacific atoll to an urbanized Western life-style in New Zealand is associated with increases in body mass in both men and women. Both the systolic and diastolic blood pressures of migrant men are significantly higher than would be expected in this cohort on the basis of age when compared with the nonmigrants. This is consistent with a rise around the time of migration to a level which is then maintained, with the diastolic pressures taking longer than the systolic pressures to respond to the migration stimuli. Most of this rise in blood pressure may be attributed to weight gain, but a significant part of the diastolic pressure excess remains unexplained. This pattern is not exhibited by the women, which may be a reflection of the sex roles in this Polynesian society. These findings indicate a need for new immigrants to be encouraged not to gain weight when confronted with new dietary choices.

Acculturation↗
PubMed1987

Migration and gout: the Tokelau Island migrant study.

The prevalence and 14 year incidence of clinical gout and its precursors were investigated in the Polynesian population of Tokelauans living in the Pacific basin, non-migrant Tokelauans living in their isolated atoll homeland being compared with migrant Tokelauans living in urban New Zealand. The age standardised prevalence of gout in Tokelauan men in New Zealand was higher than that in non-migrant Tokelauan men, being 21.0 and 19.5/1000 subjects at the beginning of the study and 51.0 and 14.6/1000 at the end of study, respectively. Migrant men in New Zealand aged under 55 had higher mean serum uric acid concentrations than non-migrant men of the same age. The prevalence of gout was low in women in both environments. The age standardised relative risk of developing gout between 1968 and 1982 was 9.0 times higher in the migrant men than in the non-migrant men. Age, serum uric acid concentration, serum cholesterol concentration, and self reported alcohol consumption at entry to the study were the best set of predictors of gout in men. Preventive strategies to change body mass, diet, and patterns of alcohol use need to be developed in this population.

Adolescent↗
PubMed1987

24-h catecholamine excretion: relationships with age and weight.

24-hour urines were obtained from groups of volunteer subjects recruited from populations in the UK, USA, Nigeria and the South Pacific. Urines were collected during the course of normal daily activities. HPLC/electrochemical detection was used to measure concentrations of adrenaline and noradrenaline in each urine. Calculated 24-h output of catecholamines was tested for significant linear regression relationships with age, weight and 24-h urine volume in each population. Noradrenaline excretion tended to be positively related to age and to body wt. Adrenaline excretion tended to show little or no relationship with either age or body wt. Relationships based on catecholamine excretion/U creatinine were notably different to those based on absolute catecholamine excretion. Differences were observed in the nature and strength of the relationships in the different populations, indicating the likely importance of interactions with other factors.

Adult↗
PubMed1987

Rheumatic complaints in Tokelau. I. Migrants resident in New Zealand. The Tokelau Island migrant study.

The three Tokelau atolls are 8 degrees south of the equator. In 1966 the islands were involved in a severe hurricane which drew attention to overcrowding and led to resettlement of more than half the population in New Zealand. One thousand three hundred and eighty one migrants over 15 years old were examined in New Zealand in 1980 and 1981 for rheumatic complaints as part of a continuing assessment. Clinical criteria for osteoarthritis (COA), including crepitus in any joint and in the knee, showed an increase in prevalence with age and weight in both sexes. Partial correlation coefficient analysis showed an association of the number of affected joints or the severity of knee COA (COAK) with both age and weight. Stepwise regression showed that age was the best predictor of both COA and COAK scores. Weight had predictive value only for COAK and only in women. Using the tracking method, previous high and/or increasing weight was related to COAK observed at this assessment. Heberden nodes increased with age and were more prevalent in women but were not associated with weight. Low back, dorsal and neck pain showed no association with age or sex. Low back pain was associated with weight. Joint pain following injury occurred in 15.4% of men. Gout, more common in men, was the only frequent inflammatory arthritis found. Two definite cases of rheumatoid arthritis (RA) were identified and four had criteria 1 and 2 for the New York criteria.

Adolescent↗
PubMed1987

Rheumatic complaints in Tokelau. II. A comparison of migrants in New Zealand and non-migrants. The Tokelau Island migrant study.

The migration of 1381 Tokelauans 15 years and over to New Zealand leaving 811 in Tokelau, provided a unique opportunity to test centuries of speculation on the impact of environment on rheumatic disease. There was no change in all rheumatic complaints. The migrant men had more gout, joint pain following injury, and neck pain. The migrant women had more dorsal back pain. There was no change in the prevalence of clinically defined osteoarthritis (COA) despite positive associations with weight and higher weights in the migrants. Rheumatoid arthritis was infrequent in both populations. Low back pain was common but was not more common in migrants, though compensation payments are readily available in New Zealand and are not in the Islands.

Adolescent↗
PubMed1986

Hypertension among urban and rural Tongans.

A cross-sectional study of urban and rural Tongans showed the prevalence of hypertension to be 8.4%. Hypertension occurred more often in urban men than in women. Systolic blood pressure (BP) showed a significant increase with age in all groups, except among rural men. Multivariant discriminant analysis identified the characteristics that were associated with a raised BP. The independent variables were selected for entry into the analysis on the basis of their power to separate BP categories, using Rao's V as the generalized measure of distance between groups. Age and body build (BMI or Fatsum) accounted for most differences between normotensive and hypertensive persons, especially in women. The fasting plasma glucose level was a significant discriminating characteristic for both men and women. The packed red cell volume was the most powerful single discriminating characteristic in men and the serum triglyceride level in women. The use of each characteristic to classify individuals by BP category may help clinicians to use cross-sectional data when deciding on the treatment of raised BP.

Adult↗
PubMed1985

Are low cholesterol values associated with excess mortality?

The relation between cholesterol concentration and mortality was studied prospectively over 17 years in 630 New Zealand Maoris aged 25-74. The dead or alive state of each person was determined in 1981. The causes of death were divided into three categories: cancer, cardiovascular disease, and "other." Using univariate and both linear and non-linear multivariate methods of analysis for survivorship data, significant inverse relations with serum cholesterol were found for total mortality in women, for mortality from cancer in men and women, and for other causes of mortality in both men and women. The inverse and non-linear association with total mortality in women remained significant when deaths in the first five years of follow up were excluded. This suggests that the association was not explained by undetected illness causing low cholesterol concentrations at the time of initial examination.

Adult↗
PubMed1985

Mortality among New Zealand Maori and non-Maori Mormons.

Mortality rates for New Zealand Maori and non-Maori Mormons in the period 1970-77 have been compared with those for non-Mormons in the census year 1976 to measure the impact of the Mormon lifestyle on differences in mortality between Maoris and non-Maoris. Maori mortality was much lower among Mormons than non-Mormons suggesting that environmental, rather than genetic factors, play a predominant role in the relatively high overall Maori mortality. However the prevalence of smoking among Maori Mormons was not much lower than for the general Maori population. Reasons for the relative mortality advantage of Maori Mormons were therefore not clear, although attitudes to health and health services utilization, and the influence of strong social support networks, might be involved. Paradoxically, non-Maori Mormon mortality rates were similar to those for non-Mormons. A combination of factors appeared to contribute to this finding including the fact that 26% of non-Maori Mormons were of Pacific Island origin, non-Maori Mormons were of lower socioeconomic status than other non-Maoris, and part Maoris probably constitute a high, but unknown, proportion of Mormons classified as non-Maoris.

Adolescent↗
PubMed1985

Longitudinal analysis of the relationship between blood pressure and migration: the Tokelau Island Migrant Study.

The Pacific atoll population of Tokelau has been followed since 1968 to assess the health consequences of migration to a western society. The blood pressure of a cohort of 532 adults who were still living in Tokelau in 1976 (nonmigrants) are compared with those of a cohort of 280 adults who had migrated to New Zealand (migrants). Significant differences between migrants and nonmigrants were detected in the rates of change of both systolic and diastolic pressures in men, and in the rates of change of diastolic pressures in women. The age-, body mass, and blood pressure-corrected rates of change were greater in migrants than in nonmigrants, and greater in men than in women. Blood pressures tend to rise 1 mmHg/year faster among male migrants than among male nonmigrants, and about 0.4 mmHg/year faster among female migrants than among female nonmigrants. These findings have clear implications for the health of migrants.

Adolescent↗
PubMed1983

Relationship between blood pressure and modernity among Ponapeans.

In the Micronesian island of Ponape blood pressures were found in 1947 and again in 1953 to be very low and to show no difference between age groups. As part of the US Trust Territory of the Pacific from 1945, the island had begun to change in the direction of modernity, the changes being most dramatic in the capital town of Kolonia, but no part of the island being unaffected. After a generation of modernization, a cross-sectional study was done to assess the impact of changing way of life on blood pressure. Communities were sampled at three levels of impact of modernization: the capital town of Kolonia, an intermediate area, and a remote area. No differences in salt intake were found for the three areas; but the population in the most modern area was younger and heavier. No consistent ecological differences were found in blood pressure level. Since there is considerable variation in modernity within each area, a Guttman-type scale of individual modernity was developed. No trends of variation of blood pressure with modernization were found to be consistent for both sexes and all areas. However, among males in the most modern area both systolic and diastolic pressures increased consistently with increasing modernity, controlling for age. For diastolic pressures, significant increases were found for all males, Kolonia males, and intermediate area males. When body mass as well as age were controlled, the strength of the trends decreased. But among Kolonia males the increase of diastolic pressure with increasing modernity remained highly significant; that of systolic pressure, marginally significant.

Adult↗
PubMed1983

Observations on rheumatic disease in Polynesia and the Philippines.

Two different types of study of rheumatic disease in the southwest Pacific are outlined. The Philippines study of a rural developing population is primarily oriented to intervention rather than causation, but before intervention can be effectively planned, information on the frequency and causes of rheumatic complaints is necessary. The Tokelauan investigation is a comprehensive prospective study of the total population with full medical examination of each subject allowing hypotheses to be tested concerning genetic and environmental variables.

Adolescent↗