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.

Profile of the female athlete triad among elite Kenyan endurance athletes and non-athletes

Women participating in endurance sports are at risk of presenting with low energy availability (EA), menstrual dysfunction (MD), and low bone mineral density (BMD), collectively termed the female athlete triad (FAT or TRIAD). Therefore, the purpose of the study was to determine the profile of the TRIAD among elite Kenyan female athletes and among non-athletes. There were 39 participants (athletes: 25, non-athletes:14) who provided the data for this study. Exercise energy expenditure (EEE) was deducted from energy intake (EI), and the remnant energy normalized to fat free mass (FFM) to determine energy availability (EA). Weight of all food and liquid consumed during three consecutive days determined EI. EEE was determined after isolating and deducting energy expended in exercise or physical activity above lifestyle from the total energy expenditure output as measured by Actigraph GT3X+. Dual energy x-ray absorptiometry (DXA) determined both FFM and BMD. Menstrual function was determined from a daily temperature-menstrual log kept by each participant for nine continuous months. Low EA (<45 kcal/kgFFM.d-1) was evident in 61.53% of the participants (athletes: 28.07 ±11.45 kcal/kgFFM.d-1, non-athletes: 56.97 ±21.38 kcal/kgFFM.d-1). The overall 36% MD seen among all participants was distributed as 40% among the athletes, and 29% among non-athletes. None of the athletes was amenorrheic. Low BMD was seen in 79% of the participants (athletes: 76%, non-athletes:86%). Overall, 10% of the participants (athletes: 4, non-athletes: 0) showed simultaneous presence of all three components of the TRIAD. The Independent sample t-test showed significant difference (t=5.860; p< 0.001) in prevalence of the TRIAD between athletes and non-athletes. The hypothesized higher prevalence of the TRIAD among athletes compared to non-athletes was partially accepted. To alleviate conditions arising from low EA, both athletes and their coaches need regular education on how to ensure they adequately meet specific dietary and nutritional requirements for their competition events

Association between energy availability and menstrual function in elite Kenyan runners

Low energy availability (EA) has been recognized as an instigator of menstrual dysfunction and subsequent hypoestrogenism that leads to deterioration in bone health. Elite Kenyan male athletes have been reported to often function under low energy balance. Therefore, the purpose of this study was to determine EA and menstrual function (MF) among elite Kenyan female athletes; and to explore the association between EA and MF in the athletes. The data were collected from 25 elite Kenyan runners and 14 non-athletes. Energy intake (EI) minus exercise energy expenditure (EEE) normalized to fat free mass (FFM) determined EA. EI was determined through weight of all food and liquid consumed over three consecutive days. EEE was determined after isolating and deducting energy expended in exercise or physical activity above lifestyle level from the total energy expenditure output as measured by Actigraph GT3X+. FFM was assessed using DXA. A daily temperature-menstrual log kept for nine continuous months was used to establish menstrual function. Overall, EA below 45 kcal/kgFFM.d-1 was seen in 61.53% of the participants (athletes: 28.07 ±11.45 kcal/kgFFM.d-1, non-athletes:56.97 ±21.38 kcal/kgFFM.d-1). Results on menstrual dysfunction were as follows: oligomenorrhea (athletes: 40%; non-athletes: 14.3%) and amenorrhea (non-athletes: 14.3%). None of the athletes were amenorrheic. Results did not show any significant association between EA and MF, but the low to sub-optimal EA among elite Kenyan female athletes raises concern for their future menstrual and bone health. . Educating the athletes and coaches will enhance achievement of the specific dietary and nutritional needs appropriate to their competition events

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.

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.

Post-prandial glucose levels and consumption of omega 3 fatty acids and saturated fats among two rural populations in Kenya.

BACKGROUND: Amount and quality of dietary fat modifies glucose tolerance. Omega 3 Fatty Acids (n-3F A) are polyunsaturated fats, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found primarily in fish and they have a positive effect on glucose tolerance. OBJECTIVE: To compare risk of type 2 diabetes mellitus (T2DM), as demonstrated thourough impaired glucose tolerance (IGT), and n-3FA intake among two rural populations. DESIGN: A descriptive, cross-sectional comparative study. SETTING: Bondo District (Luo Community) and Kericho District (Kipsigis Community) of the Lake Victoria basin of Kenya. SUBJECTS: Sample of 150 individuals, aged above 18 years was randomly selected from each of the two communities. INTERVENTIONS: Impaired glucose tolerance (IGT) was measured according to World Health Organisation diagnostic criteria. The intake of n-3FA was determined using a 24 hour dietary recall and food frequency schedule. Data was analysed using SPSS and Pearson Correlation Coefficient was used to test correlation between n-3FA consumption and IGT. The inter-group comparisons were done using the t-test and analysis of variance. RESULTS: The prevalence of IGT was 11.8% among the Kipsigis and 4.8% among the Luo (P<0.001). The mean EPA and DHA intake was found to be 0.29 g/day and 0.34 g/day respectively among the Luo and 0.01 g/day and 0.01 g/day among the Kipsigis (P<0.001). The relationship between 2 hour post-prandial glucose level and consumption of DHA was (r=-0.111, p<0.05), EPA (r=-0.123, p<0.05), polyunsaturated fatty acids (r=-0.128, p<0.05) and saturated fats (r=-0.002, p=0.973). CONCLUSION: The levels of IGT were significantly lower (P<0.001) among the Luo, than among the Kipsigis. There was also evidence of significant inverse relationship between IGT and consumption of n-3FA and polyunsaturated fatty acids (PUFA) but no association between saturated fats intake and IGT. The saturated fat ingested did not affect the level of post-prandial glucose. The Luo who consumed higher n-3FA amounts, recorded lower levels of IGT than the Kipsigis who had significantly lower consumption. RECOMMENDATIONS: Effective screening methods should be used at the existing health units to determine risk factors of type 2 diabetes mellitus like IGT among patients. This could help in advising them accordingly on lifestyle changes, especially concerning diet and beneficial fats.

Food and macronutrient intake of elite kenyan distance runners.

The food and macronutrient intake of elite Kenyan runners was compared to recommendations for endurance athletes. Estimated energy intake (EI: 2987 +/- 293 kcal; mean +/- standard deviation) was lower than energy expenditure (EE: 3605 +/- 119 kcal; P < 0.001) and body mass (BM: 58.9 +/- 2.7 kg vs. 58.3 +/- 2.6 kg; P < 0.001) was reduced over the 7-d intense training period. Diet was high in carbohydrate (76.5%, 0.4 g/kg BM per day) and low in fat (13.4 %). Protein intake (10.1 %; 1.3 g/kg BM per day) matched recommendations for protein intake. Fluid intake was modest and mainly in the form of water (1113 +/- 269 mL; 0.34 +/- 0.16 mL/kcal) and tea (1243 +/- 348 mL). Although the diet met most recommendations for endurance athletes for macronutrient intake, it remains to be determined if modifying energy balance and fluid intake will enhance the performance of elite Kenyan runners.