Ten-year fracture risk predicted by proximal femur Hounsfield units.

Colon cancer screening occurs at younger ages than osteoporosis screening. Bone density measurements using virtual colonoscopy performed for colon cancer screening can provide an early warning sign of patients at potential risk for osteoporosis-related fractures. Earlier identification may improve treatment and potentially fracture prevention. INTRODUCTION: Opportunistic osteoporosis screening with computed tomography colonography (CTC) offers an opportunity to capitalize on earlier colorectal cancer screening to identify patients at risk of future fractures. The purpose of this study is to evaluate 10-year fracture and specifically hip fracture risk based on Hounsfield units (HU) obtained from CTC. METHODS: We identified all CTC scans between 2004 and 2007 of patients 40 years and older with 10 years minimum follow-up. Hounsfield units were measured within the proximal femur and fractures identified via worldwide military records. Patients were stratified into two cohorts based on the presence or lack of a fracture in the wrist, spine, hip, or proximal humerus. Hounsfield unit measurements were compared between groups using Student's t test and the HU threshold was calculated that best approximated an 80% sensitivity to optimally screen patients for fracture risk. The odds ratio, negative predictive value, 10-year incidence of fracture, and survival curves were calculated. RESULTS: We identified 3711 patients with 183 fractures over 10 years. The HU threshold that corresponded with an 80% sensitivity to identify fractures was 112 HU. The negative predictive value (NPV) for overall fractures and hip fractures was over 97%. The 10-year fracture incidence was higher in patients below 112 HU compared to those above for both overall fractures (6.3% vs 1.7%) and hip fractures (2.7% vs 0.07%). The 112 HU threshold corresponds with an odds ratio for overall fracture and hip fractures of 2.5 (95% confidence interval (CI), 1.7-3.6) and 24.5 (95% CI, 3.3-175.5), respectively. CONCLUSION: In the 10 years following CTC, patients who experienced a fracture had lower hip HU. Decreasing HU on CTC may be an early warning sign of fracture potential.

Health-care coverage and access to health care in the context of type 2 diabetes and hypertension in rural Mexico: a systematic literature review.

OBJECTIVE: We aimed to identify the coverage rates and use of health care and to explore barriers and facilitators of access in rural Mexico. STUDY DESIGN: Systematic review of the literature. METHODS: We undertook a structured search in the electronic databases EMBASE, Medline, and Scopus. Inclusion criteria comprised articles published in Spanish and English during the period 1986-2018. The studies were screened and selected by two independent reviewers in accordance with predefined criteria. RESULTS: The review included 14 studies. Over the last 30 years, the rates of health-care coverage have increased from 30% to >50% in rural Mexico. Although the rates of health-care coverage increased, aspects such as lack of resources, language, and health-care professionals remained important barriers to health care. Cash transfer programs were identified as a facilitator. CONCLUSIONS: Despite increased health-care coverage of >50% in the last three decades, action is needed to fulfill the needs of rural Mexican populations. It is important to increase the number of trained health professionals who practice in rural areas. Moreover, health programs should be developed and adapted to meet the needs of rural and indigenous populations.

Anthropometric measures and their association with risk factors for cardio-metabolic diseases in Kenyan adults.

BACKGROUND: The prevalence of cardio-metabolic diseases (CMD) is drastically increasing worldwide. Anthropometric measures of fat accumulation are correlated with CMD and Metabolic Syndrome (MS), but few studies have addressed this association in sub-Saharan African populations. AIM: To investigate the association between anthropometric features, MS and other CMD risk factors in a population from Kenya. SUBJECTS AND METHODS: In this cross-sectional study including 1405 Kenyans, anthropometric measurements including visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (SAT) were carried out. Fasting blood glucose and standard oral glucose tolerance test, fasting serum insulin and plasma lipids were analysed. Homeostatic model assessment of insulin resistance was calculated. Systolic and diastolic blood pressures were measured. RESULTS: CMD risk factors and MS were associated with all anthropometric features, except for high-density lipoprotein cholesterol levels (p < 0.05). The strongest association between MS and anthropometrics was seen with SAT (ß = 1.45 ± 0.32 in men and 0.88 ± 0.14 in women, both p < 0.05). CONCLUSIONS: Anthropometric measures, especially features of central obesity such as VAT and SAT, are relevant indicators of cardio-metabolic health in Kenyan populations. SAT is the strongest predictor of MS. These results highlight the need for further research on the pathological implication of VAT and SAT, in order to understand patterns of fat distribution and cardio-metabolic health among different ethnic groups.

Deriving an optimal threshold of waist circumference for detecting cardiometabolic risk in sub-Saharan Africa.

BACKGROUND: Waist circumference (WC) thresholds derived from western populations continue to be used in sub-Saharan Africa (SSA) despite increasing evidence of ethnic variation in the association between adiposity and cardiometabolic disease and availability of data from African populations. We aimed to derive a SSA-specific optimal WC cut-point for identifying individuals at increased cardiometabolic risk. METHODS: We used individual level cross-sectional data on 24 181 participants aged ⩾15 years from 17 studies conducted between 1990 and 2014 in eight countries in SSA. Receiver operating characteristic curves were used to derive optimal WC cut-points for detecting the presence of at least two components of metabolic syndrome (MS), excluding WC. RESULTS: The optimal WC cut-point was 81.2 cm (95% CI 78.5-83.8 cm) and 81.0 cm (95% CI 79.2-82.8 cm) for men and women, respectively, with comparable accuracy in men and women. Sensitivity was higher in women (64%, 95% CI 63-65) than in men (53%, 95% CI 51-55), and increased with the prevalence of obesity. Having WC above the derived cut-point was associated with a twofold probability of having at least two components of MS (age-adjusted odds ratio 2.6, 95% CI 2.4-2.9, for men and 2.2, 95% CI 2.0-2.3, for women). CONCLUSION: The optimal WC cut-point for identifying men at increased cardiometabolic risk is lower (⩾81.2 cm) than current guidelines (⩾94.0 cm) recommend, and similar to that in women in SSA. Prospective studies are needed to confirm these cut-points based on cardiometabolic outcomes.International Journal of Obesity advance online publication, 31 October 2017; doi:10.1038/ijo.2017.240.

Comparative study of HbA1c and fasting plasma glucose vs the oral glucose tolerance test for diagnosis of diabetes in people with tuberculosis.

AIM: To compare HbA1c and fasting plasma glucose assessment, with the 2-h oral glucose tolerance test as reference, in screening for diabetes in people with turberculosis. METHODS: Individuals (N=268) with newly diagnosed smear-positive tuberculosis were screened for diabetes at a tertiary hospital in Lahore, Pakistan. Diabetes diagnosis was based on WHO criteria: thresholds were ≥48 mmol/mol (≥6.5%) for HbA1c and ≥7.0mmol/l for fasting plasma glucose. RESULTS: The proportion of participants diagnosed with diabetes was 4.9% (n =13) by oral glucose tolerance test, while 11.9% (n =32) and 14.6% (n =39) were diagnosed with diabetes using HbA1c and fasting plasma glucose criteria, respectively. The area under the receiver-operating characteristic curve was 0.79 (95% CI 0.64 to 0.94) for HbA1c and 0.61 (95% CI 0.50 to 0.73) for fasting plasma glucose, with a borderline significant difference between the two tests (P=0.07). CONCLUSIONS: HbA1c and fasting plasma glucose performed equally in terms of diagnosing new diabetes cases in individuals with tuberculosis, but the proportion of participants falsely classified as positive was higher for fasting plasma glucose. This may be explained by acute blood glucose fluctuations when using fasting plasma glucose. HbA1c may be a more reliable test in individuals with transient hyperglycaemia.

Geographic differences in the associations between impaired glucose regulation and cardiovascular risk factors among young adults.

AIMS: To assess geographic differences in the association between BMI, blood pressure and lipid levels with impaired glucose regulation among young adults from various geographical regions. METHODS: This was a cross-sectional study including data from 6987 participants aged ≤ 30 years from India, Singapore, Australia, Greenland, Kenya and Tanzania. Impaired glucose regulation was determined by the 75-g oral glucose tolerance test. For each geographical region, BMI, blood pressure and lipids were examined and compared between participants with normal glucose tolerance and those with impaired glucose regulation. Multiple logistic regression models were used to assess the association between risk factors and impaired glucose regulation. RESULTS: Indian and East African people had a higher prevalence of impaired glucose regulation compared with participants from other regions, despite their lower BMI. Compared with the other regions, blood pressure was lower among Indian and Singaporean people but higher in those from Greenland. Greenlanders had the highest, while Indian and East-African people, had the lowest level of HDL cholesterol. BMI was positively associated with impaired glucose regulation in all regions, and there were no statistically significant geographic differences. In the Indian, Singaporean and Australian participants, there was a positive association between blood pressure and impaired glucose regulation. Triglycerides were positively associated with and HDL cholesterol had no association with impaired glucose regulation in all geographical regions. CONCLUSIONS: Higher BMI and triglyceride levels were positively associated with prevalent impaired glucose regulation in all geographical regions. There were geographic differences in the association between impaired glucose regulation and blood pressure and lipids, probably reflecting environmental and genetic factors.

Physical activity and capacity at initiation of antiretroviral treatment in HIV patients in Ethiopia.

SUMMARY We described levels of habitual physical activity and physical capacity in HIV patients initiating antiretroviral treatment in Ethiopia and assessed the role of HIV and nutritional indicators on these outcomes. Physical activity energy expenditure (PAEE) and activity levels were measured with combined heart rate and movement sensors. Physical capacity was assessed by grip strength, sleeping heart rate and heart rate economy. Grip strength data was also available from a sex- and age-matched HIV-negative reference group. Median PAEE was 27.9 (interquartile range 17.4-39.8) kJ/kg per day and mean ± s.d. grip strength was 23.6 ± 6.7 kg. Advanced HIV disease predicted reduced levels of both physical activity and capacity; e.g. each unit viral load [log(1+copies/ml)] was associated with -15% PAEE (P < 0.001) and -1.0 kg grip strength (P < 0.001). Grip strength was 4.2 kg lower in patients compared to HIV-negative individuals (P < 0.001). Low body mass index (BMI) predicted poor physical activity and capacity independently of HIV status, e.g. BMI <16 was associated with -42% PAEE (P < 0.001) and -6.8 kg grip strength (P < 0.001) compared to BMI ≥18.5. The study shows that advanced HIV and malnutrition are associated with considerably lower levels of physical activity and capacity in patients at initiation of antiretroviral treatment.

The use of combined heart rate response and accelerometry to assess the level and predictors of physical activity in tuberculosis patients in Tanzania.

SUMMARY: We assessed the role of tuberculosis (TB) disease and HIV infection on the level of physical activity. A combined heart rate and movement sensor was used to assess habitual physical activity in TB patients and non-TB controls. The association between sputum-negative TB, sputum-positive TB, HIV and physical activity estimates were assessed in multivariable linear regression models adjusted for age, sex, haemoglobin and alpha-1-acid glycoprotein (AGP). Sputum-positive [eB 0·43, 95% confidence interval (CI) 0·29-0·64] and sputum-negative (eB 0·67, 95% CI 0·47-0·94) TB as well as HIV infection (eB 0·59, 95% CI 0·46-0·75) were associated with reduced activity compared to controls. Anaemia accounted for a substantial part of the effects of HIV, while elevated AGP primarily mediated the TB effect. The level of physical activity is highly influenced by TB and HIV, and mainly mediated through anaemia of infection and associated with elevated acute phase response.

Sleep duration and sleep quality are associated differently with alterations of glucose homeostasis.

AIMS: Studies suggest that inadequate sleep duration and poor sleep quality increase the risk of impaired glucose regulation and diabetes. However, associations with specific markers of glucose homeostasis are less well explained. The objective of this study was to explore possible associations of sleep duration and sleep quality with markers of glucose homeostasis and glucose tolerance status in a healthy population-based study sample. METHODS: The study comprised 771 participants from the Danish, population-based cross-sectional 'Health2008' study. Sleep duration and sleep quality were measured by self-report. Markers of glucose homeostasis were derived from a 3-point oral glucose tolerance test and included fasting plasma glucose, 2-h plasma glucose, HbA(1c), two measures of insulin sensitivity (the insulin sensitivity index(0,120) and homeostasis model assessment of insulin sensitivity), the homeostasis model assessment of ß-cell function and glucose tolerance status. Associations of sleep duration and sleep quality with markers of glucose homeostasis and tolerance were analysed by multiple linear and logistic regression. RESULTS: A 1-h increment in sleep duration was associated with a 0.3 mmol/mol (0.3%) decrement in HbA(1c) and a 25% reduction in the risk of having impaired glucose regulation. Further, a 1-point increment in sleep quality was associated with a 2% increase in both the insulin sensitivity index(0,120) and homeostasis model assessment of insulin sensitivity, as well as a 1% decrease in homeostasis model assessment of ß-cell function. CONCLUSIONS: In the present study, shorter sleep duration was mainly associated with later alterations in glucose homeostasis, whereas poorer sleep quality was mainly associated with earlier alterations in glucose homeostasis. Thus, adopting healthy sleep habits may benefit glucose metabolism in healthy populations.

Cardiorespiratory fitness and physical activity in Luo, Kamba, and Maasai of rural Kenya.

BACKGROUND: Although habitual physical activity energy expenditure (PAEE) and cardio-respiratory fitness (CRF) are now well-established determinants of metabolic disease, there is scarcity of such data from Africa. The aim of this study was to describe objectively measured PAEE and CRF in different ethnic populations of rural Kenya. METHODS: A cross-sectional study was done among 1,099 rural Luo, Kamba, and Maasai of Kenya. Participants were 17-68 years old and 60.9% were women. Individual heart rate (HR) response to a submaximal steptest was used to assess CRF (estimated VO(2) max). Habitual PAEE was measured with combined accelerometry and HR monitoring, with individual calibration of HR using information from the step test. RESULTS: Men had higher PAEE than women (∼78 vs. ∼67 kJ day(-1) kg(-1) , respectively). CRF was similar in all three populations (∼38 and ∼43 mlO(2) ·kg(-1) min(-1) in women and men, respectively), while habitual PAEE measures were generally highest in the Maasai and Kamba. About 59% of time was spent sedentary (<1.5 METs), with Maasai women spending significantly less (55%). Both CRF and PAEE were lower in older compared to younger rural Kenyans, a difference which was most pronounced for PAEE in Maasai (-6.0 and -11.9 kJ day(-1) kg(-1) per 10-year age difference in women and men, respectively) and for CRF in Maasai men (-4.4 mlO(2) ·min(-1) kg(-1) per 10 years). Adjustment for hemoglobin did not materially change these associations. CONCLUSION: Physical activity levels among rural Kenyan adults are high, with highest levels observed in the Maasai and Kamba. The Kamba may be most resilient to age-related declines in physical activity.

Renin angiotensinogen system gene polymorphisms and essential hypertension among people of West African descent: a systematic review.

This systematic review investigates the high level of hypertension found among urban dwellers in West Africa and in the West African Diaspora in the Americas in relation to variants within the genes encoding the renin angiotensinogen system. For comparison, the results from the Caucasian populations are reviewed as well. Through a PubMed search, 1252 articles were identified and 28 eligible articles assessed in detail of which 13 included a Caucasian population. The results suggest that among the people of West African descent and among the people of Caucasian descent, hypertension is partly related to a number of single nucleotide polymorphisms (SNPs) and haplotypes in the renin gene, the angiotensinogen gene, the angiotensinogen I-converting enzyme gene and the angiotensinogen II type 1 receptor gene. Concordance between these two populations was found for some SNPs. However, for others, it was found that the SNPs associating with hypertension and the disease allele frequencies differed between these populations. Understanding the importance of these variants in a modern life setting may assist our understanding of the increased risk of developing hypertension among West Africans. Because of inconsistency in the results, low statistical power and methodological differences between studies, these results can only be taken as indicative of an association.

Vitamin and mineral intake of twelve adolescent male Kalenjin runners in western Kenya.

OBJECTIVE: To determine whether the diet of adolescent male Kalenjin runners in a boarding school setting was adequate compared to FAO/WHO recommendations. DESIGN: A cross-sectional design study. SETTING: Marakwet High School in western Kenya. SUBJECTS: A study of twelve adolescent male Kalenjin runners was carried out to determine their micronutrient intake. MAIN OUTCOME MEASURES: Over a two-week period, samples of the main eaten food were collected for analysis of micronutrient distribution and a daily 24 recall interview performed to determine additional food intake. RESULTS: The estimated intakes were compared to recommended or suggested adequate daily intake (RSDI) by FAO/WHO. For vitamin A, pyridoxine, folic acid, vitamin B12, vitamin C, and vitamin E, the intakes represented only 17%, 82%, 56%, 55%, 95%, and 65% of RSDI, respectively. In contrast, the intakes of thiamine. riboflavin, and niacin all met RSDI by 208%, 107%, and 131%, respectively. Similarly, the intakes of magnesium, iron, and zinc were 272%, 404%, and 122% of RSDI, respectively, while calcium and selenium were below, 47% and 49%, respectively. The daily intakes of phosphorous, copper, and chromium were estimated to 4214 mg, 1309 microg, and 79 microg, respectively. CONCLUSION: Total daily micronutrient intake of the twelve Kalenjin runners was far from adequate compared to FAO/WHO daily recommended and suggested adequate intake.

Calibration of bioelectrical impedance analysis for body composition assessment in Ethiopian infants using air-displacement plethysmography.

BACKGROUND/OBJECTIVES: Assessment of infant body composition (BC) is crucial to understand the consequences of suboptimal nutritional status and postnatal growth, and the effects of public health interventions. Bioelectrical impedance analysis (BIA) is a feasible, relatively inexpensive and noninvasive method for assessing BC. However, very little research has been conducted in low- and middle-income populations, where efforts to prevent or treat malnutrition in early life are a public health priority. We aimed to develop equations for predicting fat-free mass (FFM) and fat mass (FM) based on BIA in 0- to 6-month-old Ethiopian infants. SUBJECTS/METHODS: The study comprised a total of 186 BC assessments performed in 101 healthy infants, delivered at Jimma University Specialized Hospital. Infant air-displacement plethysmography (IADP) was the criterion method, whereas weight, length, sex, age and an impedance index (L(2)/Z50) were predictors. Prediction equations were developed using stepwise multiple linear regression and the accuracy was evaluated with a 10-fold cross-validation approach. RESULTS: A linear regression model based on body weight, age and sex predicted FFM, estimated by IADP, with an adjusted R(2) and root mean square error (RMSE) of 0.94 and 200 g, respectively. Adding impedance index to the model resulted in a significantly improved model fit (R(2)=0.95; RMSE=181 g). For infants below 3 months of age, inclusion of impedance index did not contribute to an improved model fit for predicting FFM compared with a model already comprising weight, sex and age. CONCLUSIONS: The derived equations predicted FFM with acceptable accuracy and may be used in future field surveys, epidemiological studies and clinical trials conducted in similar sub-Saharan African population groups aged 0-6 months.

Effects of an outdoor bicycle-based intervention in healthy rural Indian men with normal and low birth weight.

Physical inactivity and low birth weight (LBW) may lead to an increased risk for developing type 2 diabetes. The extent to which LBW individuals may benefit from physical exercise training when compared with those with normal birth weight (NBW) controls is uncertain. We assessed the impact of an outdoor exercise intervention on body composition, insulin secretion and action in young men born with LBW and NBW in rural India. A total of 61 LBW and 56 NBW healthy young men were recruited into the study. The individuals were instructed to perform outdoor bicycle exercise training for 45 min every day. Fasting blood samples, intravenous glucose tolerance tests and bioimpedance body composition assessment were carried out. Physical activity was measured using combined accelerometry and heart rate monitoring during the first and the last week of the intervention. Following the exercise intervention, the LBW group displayed an increase in physical fitness [55.0 ml (O2)/kg min (52.0-58.0)-57.5 ml (O2)/kg min (54.4-60.5)] level and total fat-free mass [10.9% (8.0-13.4)-11.4% (8.0-14.6)], as well as a corresponding decline in the ratio of total fat mass/fat-free mass. In contrast, an increase in total fat percentage as well as total fat mass was observed in the NBW group. After intervention, fasting plasma insulin levels, homoeostasis model assessments (HOMA) of insulin resistance (HOMA-IR) and insulin secretion (HOMA-IS), improved to the same extent in both the groups. In summary, young men born with LBW in rural India benefit metabolically from exercise training to an extent comparable with NBW controls.

Ascaris suum antigens incorporated into liposomes used to stimulate protection to migrating larvae.

Four- to 8-week-old SPF pigs were immunized, using antigens of Ascaris suum incorporated into liposomes, via intestinal cannula or orally. Avridine was also incorporated in the liposomes in one experiment and interleukin-2 (IL-2) injected into pigs in another experiment. A priming dose of embryonate eggs (80-470 eggs/pig) were given in four of six experiments. Compared to control animals, the greatest protection of pigs to migrating ascarid larvae from a challenge dose of 10,000 embryonated eggs occurred where pigs received (1) a priming dose of eggs plus second-stage ascarid larval wall incorporated into liposomes, with or without avridine or IL-2, or (2) a priming dose of eggs plus ascarid intestinal aminopeptidase incorporated into liposomes with IL-2. The degree of protection was not statistically significant due, in part, to the variability in the responses of animals in the same treatment groups and the small number of animals per group. In general, only low titers of specific serum antibodies were detected and specific antibodies were not detected in the intestinal washing.

Insulin resistance and beta-cell function in different ethnic groups in Kenya: the role of abdominal fat distribution.

Little is known about the pathophysiology of diabetes in Africans. Thus, we assessed whether insulin resistance and beta-cell function differed by ethnicity in Kenya and whether differences were modified by abdominal fat distribution. A cross-sectional study in 1,087 rural Luo (n = 361), Kamba (n = 378), and Maasai (n = 348) was conducted. All participants had a standard 75-g oral glucose tolerance test (OGTT). Venous blood samples were collected at 0, 30, and 120 min. Serum insulin was analysed at 0 and 30 min. From the OGTT, we assessed the homoeostasis model assessment of insulin resistance by computer model, early phase insulin secretion, and disposition index (DI) dividing insulin secretion by insulin resistance. Abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) thickness were carried out by ultrasonography. Linear regression analyses were done to assess ethnic differences in insulin indices. The Maasai had 32 and 17% higher insulin resistance than the Luo and Kamba, respectively (p < 0.001). Early phase insulin secretion was 16% higher in the Maasai compared to the Luo (p < 0.001). DI was 12% (p = 0.002) and 10% (p = 0.015) lower in the Maasai compared to the Luo and Kamba, respectively. Adjustments of SAT (range 0.1-7.1 cm) and VAT (range 1.5-14.2 cm) largely explained these inter-group differences with the Maasai having the highest combined abdominal fat accumulation. The Maasai had the highest insulin resistance and secretion, but the lowest relative beta-cell function compared to the Luo and Kamba. These differences were primarily explained by abdominal fat distribution.

The role of anthropometric and other predictors for diabetes among urban Tanzanians with tuberculosis.

BACKGROUND: As diabetes impairs tuberculosis (TB) treatment outcomes, it is essential to identify diabetes among TB patients. While little is known about predictors of diabetes among healthy individuals in Africa, predictors among TB patients are almost non-existent. OBJECTIVE: To assess potential predictors for diabetes among newly diagnosed pulmonary TB patients in Tanzania. METHODS: TB patients were tested for diabetes using an oral glucose tolerance test, demographic information was collected and anthropometric measurements taken. The association between diabetes and possible predictors were examined using logistic regression analyses. RESULTS: Of 1205 TB patients, 16.4% (n = 197) had diabetes, 9.0% (n = 108) were aged ≥55 years, 3.3% (n = 40) were overweight (body mass index [BMI] ≥ 25 kg/m(2)) and 12.7% (n = 152) severely underweight (BMI < 16 kg/m(2)). Diabetes was most prevalent in the 45-55 year age group, and increasing weight, BMI and waist circumference were associated with diabetes. Severe underweight (BMI < 16 kg/m(2)) among male TB patients (sex-BMI interaction, P = 0.02) was associated with diabetes (OR 2.52, P = 0.004). CONCLUSION: Diabetes is a common comorbidity among TB patients. Although diabetes was associated with obesity and was more prevalent among the middle-aged, the majority of TB patients with diabetes comorbidity were young and lean. With diabetes as a major risk factor for TB, and with the lack of strong predictors for diabetes, universal diabetes screening should be implemented in the TB programme.

Glucose intolerance in the West African Diaspora: a skeletal muscle fibre type distribution hypothesis.

In the United States, Black Americans are largely descendants of West African slaves; they have a higher relative proportion of obesity and experience a higher prevalence of diabetes than White Americans. However, obesity rates alone cannot explain the higher prevalence of type 2 diabetes. Type 2 diabetes is characterized by insulin resistance and beta-cell dysfunction. We hypothesize that the higher prevalence of type 2 diabetes in African Americans (as compared to White Americans) is facilitated by an inherited higher percentage of skeletal muscle fibre type II and a lower percentage of skeletal muscle fibre type I. Skeletal muscle fibre type II is less oxidative and more glycolytic than skeletal muscle fibre type I. Lower oxidative capacity is associated with lower fat oxidation and a higher disposal of lipids, which are stored as muscular adipose tissue in higher amounts in Black compared to White Americans. In physically active individuals, the influence of muscle fibre composition will not be as detrimental as in physically inactive individuals. This discrepancy is caused by the plasticity in the skeletal muscle fibre characteristics towards a higher activity of oxidative enzymes as a consequence of physical activity. We suggest that a higher percentage of skeletal muscle fibre type II combined with physical inactivity has an impact on insulin sensitivity and high prevalence of type 2 diabetes in Blacks of West African ancestry.

Prevalence of glucose intolerance and associated risk factors in rural and urban populations of different ethnic groups in Kenya.

OBJECTIVE: To assess the prevalence of glucose intolerance in rural and urban Kenyan populations and in different ethnic groups. Further, to identify associations between lifestyle risk factors and glucose intolerance. RESEARCH DESIGN AND METHODS: A cross-sectional study included an opportunity sample of Luo, Kamba, Maasai, and an ethnically mixed group from rural and urban Kenya. Diabetes and IGT were diagnosed using a standard OGTT. BMI, WC, AFA, AMA and abdominal subcutaneous and visceral fat thicknesses, physical activity and fitness were measured. Questionnaires were used to determine previous diabetes diagnosis, family history of diabetes, smoking habits, and alcohol consumption. RESULTS: Among 1459 participants, mean age 38.6 years (range 17-68 years), the overall age-standardized prevalence of diabetes and IGT was 4.2% and 12.0%. The Luo had the highest prevalence of glucose intolerance among the rural ethnic groups. High BMI, WC, AFA, abdominal visceral and subcutaneous fat thickness, low fitness and physical activity, frequent alcohol consumption, and urban residence were associated with glucose intolerance. CONCLUSIONS: The prevalence of diabetes and IGT among different Kenyan population groups was moderate, and highest in the Luo. The role of lifestyle changes and ethnicity on the effect of diabetes in African populations needs further exploration.

Mineral content of traditional leafy vegetables from western Kenya.

Socio-economic changes that have taken place in Africa have influenced people's eating habits in both rural and urban set-ups. Most people prefer introduced foods to traditional foods, including plant foods whose consumption is widely regarded as a primitive culture manifesting poor lifestyles. However, recent studies on traditional plant foods have shown that some are highly nutritious; containing high levels of both vitamins and minerals. They also have potential as a remedy to counter food insecurity since most are well adapted to the local environment, enabling them to resist pests, drought and diseases. This paper describes the mineral (calcium, iron and zinc) contents in some 54 traditional vegetable species collected from Nyang'oma area of Bondo district, western Kenya. Atomic absorption spectroscopy was used to determine the mineral content. We found that most traditional leafy vegetables, domesticated and wild, generally contain higher levels of calcium, iron and zinc compared with the introduced varieties such as spinach (Spanacia oleracea), kale (Brassica oleracea var. acephala) and cabbage (Brassica oleracea var. capitata). The results of this study could contribute towards identification, propagation and subsequent domestication and cultivation promotion of nutrient-rich and safe species within the farming systems of the local communities in Kenya, sub-Saharan Africa or elsewhere.