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Biomedical subjects

N C Unwin

Publications and source records attributed to N C Unwin.

24 records · Page 2Linked to original sources

Serum concentrations of vitamins A and E in impaired glucose tolerance.

Serum concentrations of vitamins A and E were measured in 32 subjects with impaired glucose tolerance (IGT) and 148 subjects with normal glucose tolerance using reversed-phase high-performance liquid chromatography. Fasting glucose, insulin and lipid concentrations were also measured. Serum vitamin A concentrations were higher in subjects with IGT 2.5 (1.1-3.4) vs. 2.1 (1.4-3.2) mumol/l [median (2.5-97.5 percentiles)] (P = 0.002), the difference remaining significant after adjustment for triglycerides (P = 0.028). There was a univariate association between vitamin A levels and insulin resistance (r = 0.164; P = 0.02) and in multivariate logistic regression analysis the relative risk of subjects with high vitamin A concentrations having IGT was 3.8 (P = 0.002). There were no differences in serum vitamin E concentrations between the groups. These data suggest that higher vitamin A concentrations found in non-insulin-dependent diabetes pre-date the onset of diabetes. Further studies are required to confirm this finding and to investigate the possibility of a role for vitamin A in the aetiology of diabetes and IGT.

Blood Glucose↗

The prevalence of insulin resistance and other cardiovascular disease risk factors in healthy elderly southwestern Nigerians.

We assessed the prevalence of coronary heart disease (CHD) risk factors including insulin resistance in 500 (205 males, 295 females) healthy elderly (age > 55 years) indigenous, low socioeconomic group Yorubas residents in either an urban slum (n = 240) or a rural town (n = 260) in southwestern Nigeria. Anthropometric indices, blood pressure and fasting plasma levels of glucose, lipids, insulin and insulin resistance were measured. The results indicated that: (i) gross obesity (4.4%), diabetes (1.6%), hyperlipidaemia (0.2%) and cigarette smoking (4.8%) were relatively uncommon in the population, although the prevalence of hypertension (30%) was higher than previously reported from this population; (ii). the subjects had a relatively high prevalence of multiple CHD risk factors (about 20% had > 4 risk factors), an observation considered paradoxical in view of the reportedly low CHD prevalence in this population; (iii) these CHD risk factors (increased body mass and blood pressure (BP), hyperinsulinaemia and insulin resistance) were more prevalent in the women and in urban residents; (iv) hyperinsulinaemia (20%) and insulin resistance (35%) were common in the population, and were associated, on regression analyses, to such other CHD risk factors as BP and body mass, particularly in women, suggesting, as in Caucasians, that insulin resistance could be an important index of CHD risk; and (v) the excess of multiple CHD risk factors in the women, is due at least in part, to their increased tendency to obesity (8%) and reduced physical activity (83%). This study concludes that: (i) despite the high prevalence of multiple risk factors in this population, CHD prevalence is low, indicating the supremacy of such major risk factors as diabetes and hyperlipidaemia (relatively uncommon here) in the development of CHD; and (ii) potentially the greatest CHD risk is in the elderly women especially if relatively overweight, physically inactive and resident in an urban centre. While further confirmatory studies are necessary in younger subjects and across societal socioeconomic strata, our results nonetheless suggest that attempts to maintain the CHD prevalence at low levels in this population should include efforts directed at reducing excess body weight particularly in women, and advice on maintenance of a traditional diet to keep lipid levels and diabetes prevalence low.

Age Distribution↗

Identifying Chinese populations in the UK for epidemiological research: experience of a name analysis of the FHSA register. Family Health Services Authority.

There is a paucity of research on health in the UK Chinese community partly due to the difficulties of identifying and accessing study populations. For a survey of cardiovascular disease we aimed to identify and recruit all Chinese adults aged 25-64 y living in Newcastle-upon-Tyne, UK. One thousand, eight hundred and sixty-five potential subjects were identified using a variety of methods. Of the 1702 potential subjects identified from a name analysis of the 1991 FHSA register (FHSA group), 638 students in halls of residence were excluded and the remaining 1064 were invited to participate. Non-respondents were followed up. Of the 1064, 658 (65.5%) addresses were no longer valid, 21 (2%) were reclassified as non-Chinese and no contact was made with 18 individuals (1.6%). A further 163 subjects (non-FHSA group) came forward in response to publicity, giving a total of 530 Chinese actually identified in Newcastle. Three hundred and eighty subjects took part in the study. Compared to the 1991 Census, the recruitment procedure underestimated the total population size, particularly for men and younger ages. In the FHSA group, men were significantly more likely to be current drinkers, and women were more likely to smoke and have a lower educational attainment that the non-FHSA group. There were no other important differences in the distribution of CHD risk markers in the two groups. Our experience indicates that the FHSA register is suitable for identifying Chinese but should be used alongside other complementary methods to augment samples for ethnicity and health research.

Adult↗

Cycle helmets--when is legislation justified?

The issue of mandatory cycle helmets is highly contentious. The aim of this paper is not to argue for or against legislation but to suggest criteria on which the debate should focus. This is done by attempting to answer the question: 'What criteria must be met before cycle helmet wearing is enforced?' Consideration is given to principles, precedents and consequences and four criteria are suggested. The criteria are to do with effectiveness, personal liberty, public acceptability and the promotion of the public health benefits of cycling.

Behavior Control↗

Promoting the public health benefits of cycling.

The potential health gain from increased levels of cycling in Britain is large. This paper reviews current levels of bicycle ownership and use, and the factors which influence whether or not people choose to cycle in Britain. Cycle ownership is strongly associated with affluence and children. Males cycle more than females. Boys aged 11-15 years cycle the greatest number of miles per person per week, followed by men aged 16-59 years. Cycling to work is weakly associated with affluence. Modelling cycling to work patterns suggests that hilliness, traffic danger, rainfall and longer trip lengths are important deterrents to cycling. Cyclists identify cheapness, health, convenience and enjoyment as reasons for cycling. Non-cyclists identify danger, 'unpleasantness' (e.g. traffic fumes, weather), bike security and cycling not appealing as reasons for not cycling. Part of the lack of appeal of cycling reflects negative social attitudes towards cycling. Cycling has tended to be seen as a childhood activity and incompatible with an attractive and sophisticated image. Departments of Public Health Medicine and Health Promotion, in collaboration with other sectors, have an important role to play in promoting increased levels of cycling.

Adolescent↗

Rural and urban differences in diabetes prevalence in Tanzania: the role of obesity, physical inactivity and urban living.

A population-based survey in 1996 and 1997 of 770 adults (aged > or = 15 years) from an urban district of Dares Salaam and 928 from a village in rural Kilimanjaro district (Tanzania) revealed that the prevalence of diabetes, impaired fasting glucose (IFG), overweight, obesity, and physical inactivity was higher in the urban area for men and women. The difference between urban and rural prevalence of diabetes was 3.8 [1x1-6.5]% for men and 2x9 [0x8-4.9]% for women. For IFG, the difference was 2x8 [0x3-5x3]% for men and 3x9 [1x4-6x4]% for women; for overweight and obesity, the difference was 21.5 [15.8-27.1]% and 6.2 [3x5-8.9]% for men and 17x4 [11.5-23.3]% and 12.7 [8x5-16x8]% for women, respectively. The difference in prevalence of physical inactivity was 12x5 [7.0-18.3]% for men and 37.6 [31x9-43.3]% for women. For men with diabetes, the odds for being overweight, obese and having a large waist:hip ratio were 14.1, 5.3 and 12.5, respectively; for women the corresponding values were 9x0, 10x5 and 2x4 (the last not significant) with an attributable fraction for overweight between 64% and 69%. We conclude that diabetes prevalence is higher in the urban Tanzanian community and that this can be explained by differences in the prevalence of overweight. The avoidance of obesity in the adult population is likely to prevent increases in diabetes incidence in this population.

Adult↗