Maria Jackson

Reproducibility and validity of a quantitative food-frequency questionnaire among Jamaicans of African origin.

BACKGROUND An interviewer-administered quantitative food-frequency questionnaire (FFQ) was developed to determine the energy and nutrient intakes of adult Jamaicans of African origin as part of a study of the epidemiology of diabetes and hypertension. METHODS Reproducibility of the questionnaire was investigated in 123 participants aged 25-74 years. The relative validity of the FFQ was assessed against twelve 24-hour recalls administered over 12 months in 73 of the participants. In addition, energy intakes (EI) were compared with estimated basal metabolic rates (BMR). RESULTS Reproducibility correlation coefficients (Pearson and intraclass) varied between 0.42 for retinol and 0.71 for carbohydrate, with most values falling between 0.50 and 0.60. When compared with repeated 24-hour recalls, the FFQ estimated slightly higher energy (mean 6%) and macronutrient intakes (mean 2-14%), and was within 5% when expressed as a percentage of energy intake. Micronutrients were higher by 1.19 (calcium) to 1.61 times (vitamin C). Unadjusted correlations between the FFQ and the reference method ranged from 0.20 for beta-carotene to 0.86 for alcohol. Cross-classification of nutrients into quartiles showed that 46-48% of participants in the lowest and highest quartiles were jointly classified by both methods. Misclassifications were low for most nutrients with one or two persons misclassified at the extreme quartiles. EI/BMR ratios suggested light to moderate activity levels appropriate for an urban population in a developing country. CONCLUSIONS The FFQ showed reasonable reproducibility and validity and is suitable for estimating the habitual intakes of energy and macronutrients, but was poor for some micronutrients (retinol and beta-carotene).

Use of a food frequency questionnaire to assess diets of Jamaican adults: validation and correlation with biomarkers

BackgroundAssessment of habitual diet is important in investigations of diet-disease relationships. Many epidemiological studies use the food frequency questionnaire (FFQ) to evaluate dietary intakes but few studies validate the instrument against biological markers. The aim of this study was to assess the validity and reproducibility of a previously validated 70-item food frequency questionnaire (FFQ) that was expanded to 120-items to assess diet - cancer relations.MethodsRelative validity of the FFQ was assessed against twelve 24-hour recalls administered over 12 months in 70 subjects. The FFQ was repeated after one year (FFQ2) to assess reproducibility. The validity of the FFQ was evaluated by comparing nutrient and food group intakes from 24-hour recalls with the first and second FFQ. In addition, FFQ validity for cholesterol and folate were determined through correlation with biomarkers (serum cholesterol, serum folate and whole blood folate) in 159 control subjects participating in a case-control prostate cancer study.ResultsCompared to recalls the FFQ tended to overestimate energy and carbohydrate intakes but gave no differences in intake for protein and fat. Quartile agreement for energy-adjusted nutrient intakes between FFQ2 and recalls ranged from 31.8% - 77.3% for the lowest quartile and 20.8% - 81.0% in the highest quartile. Gross misclassification of nutrients was low with the exceptions of protein, vitamin E and retinol and weighted kappa values ranged from 0.33 to 0.64 for other nutrients. Validity correlations for energy-adjusted nutrients (excluding retinol) were moderate to high (0.38- 0.86). Correlation coefficients between multiple recalls and FFQ1 ranged from 0.27 (fruits) to 0.55 (red meat); the second FFQ gave somewhat higher coefficients (0.30 to 0.61). Reproducibility correlations for the nutrients ranged from 0.50 to 0.84.Calibration of the FFQ with biochemical markers showed modest correlations with serum cholesterol (0.24), serum folate (0.25) and whole blood folate (0.33) adjusted for age, energy, body mass index and smoking.ConclusionsThe expanded FFQ had good relative validity for estimating food group and nutrient intakes (except retinol and vitamin E) and was a reliable measure of habitual intake. Associations with biomarkers were comparable to other studies.

Underreporting of energy intake in four populations of African origin.

OBJECTIVE: To investigate the frequency of dietary underreporting in four African populations in different geographic and cultural settings.SUBJECTS: Seven-hundred and forty three men and women from rural Cameroon, 1042 men and women from urban Cameroon, 857 men and women from Jamaica and 243 male and female African Caribbeans from the UK. Subjects who reported dieting or weight control were excluded.MEASUREMENTS: Habitual dietary intake was estimated with a quantitative food frequency questionnaire, developed specifically for each country. Underreporting was defined using three cut-off levels for energy intake/estimated basic metabolic rate (EI/BMRest), based on age, sex and weight, in each site.RESULTS: The EI/BMRest was highest in rural Cameroonian men at 3.07 (95% confidence interval: 2.97, 3.17) and women at 2.84 (2.74, 2.94), intermediate in urban Cameroon and Jamaica and lowest in the UK men and women at 1.44 (1.26, 1.62) and 1.41 (1.21, 1.61). This trend existed even after adjustment for age, BMI and education (P for trend<0.0001). The trend in the frequency of underreporting using the lowest cut-off level for EI/BMRest of 1.15 was 6% and 6% in rural Cameroon for women and men, respectively, 4% and 5% in urban Cameroon, 24% and 19% in Jamaica and 28% and 39% in the UK. With higher cut off levels this trend was similar.CONCLUSION: The results suggest that the frequency of dietary underreporting differs between societies and that Westernization may be one of the factors underlying this phenomenon.

Physical and psychological violence in Jamaica's health sector

OBJECTIVE To determine the prevalence of experiences with physical violence and psychological violence that health staff have had in the workplace in Jamaica, and to identify factors associated with those experiences of violence. DESIGN AND METHODS A total of 832 health staff answered the standardized questionnaire that was used in this cross-sectional study. Sampling was done at public facilities, including specialist, tertiary, and secondary hospitals in the Kingston Metropolitan Area; general hospitals in the rural parishes; and primary care centers in urban and rural areas. Sampling was also done in private hospitals and private medical centers. RESULTS Psychological violence was more prevalent than was physical violence. Verbal abuse had been experienced in the preceding year by 38.6% of the questionnaire respondents, bullying was reported by 12.4%, and physical violence was reported by 7.7%. In multivariate analyses there was a lower risk of physical violence for health staff who were 55 years or older, worked during the night, or worked mostly with mentally disabled patients, geriatric patients, or HIV/AIDS patients. Staff members working mostly with psychiatric patients faced a higher risk of physical assaults than did other health staff. Of the various health occupations, nurses were the ones most likely to be verbally abused. In terms of age ranges, bullying was more commonly experienced by health staff 40-54 years old. CONCLUSIONS Violence in the health sector workplace in Jamaica is an occupational hazard that is of public health concern. Evaluation of the environment that creates risks for violence is necessary to guide the formulation of meaningful interventions for the country.

Diet and overweight and obesity in populations of African origin: Cameroon, Jamaica and the UK

OBJECTIVES To determine the relationship of diet to overweight and obesity among populations of African origin. DESIGN AND SETTING Cross-sectional data were obtained from adults aged 25-74 years in rural Cameroon (n = 686), urban Cameroon (n = 975), Jamaica (n = 924) and Afro-Caribbeans in the UK (n = 257). Dietary data were collected using food-frequency questionnaires specifically designed for each site. Body mass index (BMI) was used as a measure of overweight. RESULTS The expected gradient in the distribution of overweight across sites was seen in females (rural Cameroon, 9.5%; urban Cameroon, 47.1%; Jamaica, 63.8%; UK, 71.6%); however, among males overweight was less prevalent in Jamaica (22.0%) than urban Cameroon (36.3%). In developing countries increased risks of overweight (BMI > or = 25 kg m(-2) were influenced by higher energy (urban Cameroonian men) and protein (Jamaican women) intakes. No dietary variables were associated with obesity (BMI > or = 30 kg m(-2) in Cameroon or Jamaica. In the UK, energy intakes were inversely related with overweight whereas increased risks of being overweight were associated with higher protein (men) and fat (women) intakes. Similarly, whereas higher protein and fat intakes in UK men and women were associated with obesity, carbohydrate intakes were associated with decreased risks of obesity in men. CONCLUSIONS Diet and overweight were associated in the UK but few dietary variables were related to overweight in Jamaica and the Cameroon. These findings suggest that associations between diet and overweight/obesity are not generalisable among populations.

Multi-institutional prostate cancer study of genetic susceptibility in populations of African descent

Prostate cancer disparities have been reported in men of African descent who show the highest incidence, mortality, compared with other ethnic groups. Few studies have explored the genetic and environmental factors for prostate cancer in men of African ancestry. The glutathione-S-transferases family conjugates carcinogens before their excretion and is expressed in prostate tissue. This study addressed the role of GSTM1 and GSTT1 deletions on prostate cancer risk in populations of African descent. This multi-institutional case-control study gathered data from the Genetic Susceptibility to Environmental Carcinogens (GSEC) database, the African-Caribbean Cancer Consortium (AC3) and Men of African Descent and Carcinoma of the Prostate Consortium (MADCaP). The analysis included 10 studies (1715 cases and 2363 controls), five in African-Americans, three in African-Caribbean and two in African men. Both the GSTM1 and the GSTT1 deletions showed significant inverse associations with prostate cancer [odds ratio (OR): 0.90, 95% confidence interval (CI) 0.83-0.97 and OR 0.88, 95% CI: 0.82-0.96, respectively]. The association was restricted to Caribbean and African populations. A significant positive association was observed between GSTM1 deletion and prostate cancer in smokers in African-American studies (OR: 1.28, 95% CI: 1.01-1.56), whereas a reduced risk was observed in never-smokers (OR: 0.66, 95% CI: 0.46-0.95). The risk of prostate cancer increased across quartiles of pack-years among subjects carrying the deletion of GSTM1 but not among subjects carrying a functional GSTM1. Gene-environment interaction between smoking and GSTM1 may be involved in the etiology of prostate cancer in populations of African descent.

Nutritional status of 11-12-year-old Jamaican children: coexistence of under- and overnutrition in early adolescence

OBJECTIVE To determine the nutritional status of a cohort of 11-12 year olds and ascertain social and demographic factors associated with under- and overweight in early adolescence. DESIGN Cross-sectional. SUBJECTS Subgroup (n = 1698) of the birth cohort (September-October 1986) of the Jamaican Perinatal Survey enrolled in schools in the Kingston Metropolitan area. One thousand and sixty-three parents or caregivers provided social and demographic information. RESULTS Undernutrition and overnutrition are of public health significance among adolescent Jamaican children. Ten per cent of 11-12 year olds had body mass index (BMI) values below the 5th percentile (boys, 10.6%; girls, 7.1%) but this prevalence is relatively low compared with other developing countries. The prevalence of stunting was low (3%). The prevalence of overweight (BMI > or = 85th percentile) (19.3%) was approaching prevalence rates found in the USA. Similar social and demographic variables were associated with thinness and fatness in males. Birth weight predicted overweight in girls. CONCLUSIONS Under- and overnutrition in early adolescence are important problems in Jamaica. There is a need to address both under- and overnutrition in adolescence in preventive and rehabilitative intervention programmes.

Increased Dietary Inflammatory Index (DII) Is Associated With Increased Risk of Prostate Cancer in Jamaican Men

Prostate cancer is the most common nonskin malignancy, and it accounts for the most cancer deaths among Jamaican males. Diet has been implicated in the etiology of prostate cancer, including through its effects on inflammation. We examined the association between a newly developed dietary inflammatory index (DII) and prostate cancer in a case-control study of 40–80 yr old Jamaican males. A total of 229 incident cases and 250 controls attended the same urology out-patient clinics at 2 major hospitals and private practitioners in the Kingston, Jamaica metropolitan area between March 2005 and July 2007. The DII was computed based on dietary intake assessed using a previously validated food frequency questionnaire (FFQ) that was expanded to assess diet and cancer in this Jamaican population. Multivariable logistic regression was used to estimate odds ratios, with DII as continuous and expressed as quartiles. Logistic regression analysis adjusted for age, total energy intake, education, body mass index, smoking status, physical activity, and family history of prostate cancer. Men in the highest quartile of the DII were at higher risk of prostate cancer [odds ratio (OR) = 2.39; 95% confidence interval (CI) = 1.14–5.04; Ptrend = 0.08] compared to men in the lowest DII quartile. These data suggest a proinflammatory diet, as indicated by increasing DII score, may be a risk factor for prostate cancer in Jamaican men.

Habitual diet in four populations of African origin: a descriptive paper on nutrient intakes in rural and urban Cameroon, Jamaica and Caribbean migrants in Britain.

BACKGROUND The prevalence of chronic diseases is increasing in West Africa, the Caribbean and its migrants to Britain. This trend may be due to the transition in the habitual diet, with increasing (saturated) fat and decreasing fruit and vegetable intakes, both within and between countries. OBJECTIVE We have tested this hypothesis by comparing habitual diet in four African-origin populations with a similar genetic background at different stages in this transition. DESIGN The study populations included subjects from rural Cameroon urban Cameroon Jamaica and African-Caribbeans in Manchester, UK all aged 25-74 years. Habitual diet was assessed by a food-frequency questionnaire, specifically developed for each country separately. RESULTS Total energy intake was greatest in rural Cameroon and lowest in Manchester for all age/sex groups. A tendency towards the same pattern was seen for carbohydrates, protein and total fat intake. Saturated and polyunsaturated fat intake and alcohol intake were highest in rural Cameroon, and lowest in Jamaica, with the intakes in the UK lower than those in urban Cameroon. The percentage of energy from total fat was higher in rural and urban Cameroon than in Jamaica and the UK for all age/sex groups. The opposite was seen for percentage of energy from carbohydrate intake, the intake being highest in Jamaica and lowest in rural Cameroon. The percentage of energy from protein increased gradually from rural Cameroon to the UK. CONCLUSIONS These results do not support our hypothesis that carbohydrate intake increased, while (saturated) fat intake decreased, from rural Cameroon to the UK.

Dietary patterns as predictors of prostate cancer in Jamaican men.

Studies of diet and prostate cancer have focused primarily on food and nutrients; however, dietary patterns examine the overall diet, particularly foods eaten in combination, and risk of disease. We evaluated the association of dietary patterns and prostate cancer and low- and high-grade subgroups in Jamaican men. In a case-control study, we enrolled 243 incident cases and 273 urology controls in Jamaican clinics, March 2005–July 2007. Dietary patterns were identified using principal component analysis. Four food patterns were identified: a “vegetable and legume” pattern, a “fast food” pattern, a “meat” pattern, and a “refined carbohydrate” pattern. Men in the highest tertile for the refined carbohydrate pattern, characterized by high intakes of rice, pasta, sugar sweetened beverages, and sweet baked foods were at increased risk of total prostate cancer [odds ratio (OR) = 2.02; 95% confidence interval (CI) = 1.05–3.87 (Ptrend = 0.029)] and low-grade disease [OR = 2.91; 95% CI = 1.18–7.13 (Ptrend = 0.019)] compared with men in the lowest tertile. The vegetable and legumes pattern (healthy), meat pattern, or fast food pattern were not associated with prostate cancer risk. These data suggest a carbohydrate dietary pattern high in refined carbohydrates may be a risk factor for prostate cancer in Jamaican men.