Biting behaviour, spatio-temporal dynamics, and the insecticide resistance status of malaria vectors in different ecological zones in Ghana.

BACKGROUND: A significant decrease in malaria morbidity and mortality has been attained using long-lasting insecticide-treated nets and indoor residual spraying. Selective pressure from these control methods influences changes in vector bionomics and behavioural pattern. There is a need to understand how insecticide resistance drives behavioural changes within vector species. This study aimed to determine the spatio-temporal dynamics and biting behaviour of malaria vectors in different ecological zones in Ghana in an era of high insecticide use for public health vector control. METHODS: Adult mosquitoes were collected during the dry and rainy seasons in 2017 and 2018 from five study sites in Ghana in different ecological zones. Indoor- and outdoor-biting mosquitoes were collected per hour from 18:00 to 06:00 h employing the human landing catch (HLC) technique. Morphological and molecular species identifications of vectors were done using identification keys and PCR respectively. Genotyping of insecticide-resistant markers was done using the TaqMan SNP genotyping probe-based assays. Detection of Plasmodium falciparum sporozoites was determined using PCR. RESULTS: A total of 50,322 mosquitoes belonging to four different genera were collected from all the study sites during the sampling seasons in 2017 and 2018. Among the Anophelines were Anopheles gambiae s.l. 93.2%, (31,055/33,334), An. funestus 2.1%, (690/33,334), An. pharoensis 4.6%, (1545/33,334), and An. rufipes 0.1% (44/33,334). Overall, 76.4%, (25,468/33,334) of Anopheles mosquitoes were collected in the rainy season and 23.6%, (7866/33,334) in the dry season. There was a significant difference (Z = 2.410; P = 0.0160) between indoor-biting (51.1%; 15,866/31,055) and outdoor-biting An. gambiae s.l. (48.9%; 15,189/31,055). The frequency of the Vgsc-1014F mutation was slightly higher in indoor-biting mosquitoes (54.9%) than outdoors (45.1%). Overall, 44 pools of samples were positive for P. falciparum CSP giving an overall sporozoite rate of 0.1%. CONCLUSION: Anopheles gambiae s.l. were more abundant indoors across all ecological zones of Ghana. The frequency of G119S was higher indoors than outdoors from all the study sites, but with higher sporozoite rates in outdoor mosquitoes in Dodowa and Kpalsogu. There is, therefore, an urgent need for a supplementary malaria control intervention to control outdoor-biting mosquitoes.

Relationship between Continuum of Hurst Exponents of Noise-like Time Series and the Cantor Set.

In this paper, we have modified the Detrended Fluctuation Analysis (DFA) using the ternary Cantor set. We propose a modification of the DFA algorithm, Cantor DFA (CDFA), which uses the Cantor set theory of base 3 as a scale for segment sizes in the DFA algorithm. An investigation of the phenomena generated from the proof using real-world time series based on the theory of the Cantor set is also conducted. This new approach helps reduce the overestimation problem of the Hurst exponent of DFA by comparing it with its inverse relationship with α of the Truncated Lévy Flight (TLF). CDFA is also able to correctly predict the memory behavior of time series.

Profile and outcomes of hospitalized patients with COVID-19 at a tertiary institution hospital in Ghana.

BACKGROUND: In high-income countries, mortality related to hospitalized patients with the Coronavirus disease 2019 (COVID-19) is approximately 4-5%. However, data on COVID-19 admissions from sub-Saharan Africa are scanty. OBJECTIVE: To describe the clinical profile and determinants of outcomes of patients with confirmed COVID-19 admitted at a hospital in Ghana. METHODS: A prospective study involving 25 patients with real time polymerase chain reaction confirmed COVID-19 admitted to the treatment centre of the University Hospital, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana from 1st June to 27th July, 2020. They were managed and followed up for outcomes. Data were analysed descriptively, and predictors of mortality assessed using a multivariate logistic regression modelling. RESULTS: The mean age of the patients was 59.3 ± 20.6 years, and 14 (56%) were males. The main symptoms at presentation were breathlessness (68%) followed by fever (56%). The cases were categorized as mild (6), moderate (6), severe (10) and critical (3). Hypertension was the commonest comorbidity present in 72% of patients. Medications used in patient management included dexamethasone (68%), azithromycin (96%), and hydroxychloroquine (4%). Five of 25 cases died (Case fatality ratio 20%). Increasing age and high systolic blood pressure were associated with mortality. CONCLUSION: Case fatality in this sample of hospitalized COVID-19 patients was high. Thorough clinical assessment, severity stratification, aggressive management of underlying co-morbidities and standardized protocols incountry might improve outcomes. FUNDING: None declared.

Analysis of meningitis outbreak data, Jaman North District, Brong Ahafo Region, Ghana.

BACKGROUND: Descriptive analysis of meningitis outbreak in Jaman North districts of Brong Ahafo Region. DESIGN: Descriptive secondary data analysis. DATA SOURCE: records of meningitis cases were extracted from case-based forms and line list. MAIN OUTCOME MEASURE: The source and pattern of outbreak. RESULTS: A total of 367 suspected cases with 44 confirmed were recorded from Jaman North during the period of January to March 2016. The mean age of those affected was 58 ± 13 years. The case fatality rate was 0.82% and the proportion of males to females was 1:1.3 (160/207). The age group most affected was 15-29 years (54.7%) and the least was 45-49 years (3.0%). Streptococcus pneumoniae formed 77.3% of confirmed cases whilst Neisseria meningitides was 20.5%. Cases with Neisseria meningitides came from a border town in La Cote d'Ivoire. CONCLUSION: A protracted propagated meningitis outbreak occurred; and the predominant bacteria strain among confirmed cases was Streptococcus pneumoniae. Cases were mainly females and the most vulnerable group were people aged 15-29 years. FUNDING: This work was funded by the authors. Author BKD was sponsored under CDC (Frontline FETP)-CDC CoAg 6NU2GGH001876.

Profile and outcomes of hospitalized patients with COVID-19 at a tertiary institution hospital in Ghana

Background: In high-income countries, mortality related to hospitalized patients with the Coronavirus disease 2019 (COVID-19) is approximately 4-5%. However, data on COVID-19 admissions from sub-Saharan Africa are scanty. Objective: To describe the clinical profile and determinants of outcomes of patients with confirmed COVID-19 admitted at a hospital in Ghana. Methods: A prospective study involving 25 patients with real time polymerase chain reaction confirmed COVID-19 admitted to the treatment centre of the University Hospital, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana from 1st June to 27th July, 2020. They were managed and followed up for outcomes. Data were analysed descriptively, and predictors of mortality assessed using a multivariate logistic regression modelling. Results: The mean age of the patients was 59.3 ± 20.6 years, and 14 (56%) were males. The main symptoms at presentation were breathlessness (68%) followed by fever (56%). The cases were categorized as mild (6), moderate (6), severe (10) and critical (3). Hypertension was the commonest comorbidity present in 72% of patients. Medications used in patient management included dexamethasone (68%), azithromycin (96%), and hydroxychloroquine (4%). Five of 25 cases died (Case fatality ratio 20%). Increasing age and high systolic blood pressure were associated with mortality. Conclusion: Case fatality in this sample of hospitalized COVID-19 patients was high. Thorough clinical assessment, severity stratification, aggressive management of underlying co-morbidities and standardized protocols incountry might improve outcomes

Supervised machine learning models applied to disease diagnosis and prognosis.

This work analyses the diagnosis and prognosis of cancer and heart disease data using five Machine Learning (ML) algorithms. We compare the predictive ability of all the ML algorithms to breast cancer and heart disease. The important variables that causes cancer and heart disease are also studied. We predict the test data based on the important variables and compute the prediction accuracy using the Receiver Operating Characteristic (ROC) curve. The Random Forest (RF) and Principal Component Regression (PCR) provides the best performance in analyzing the breast cancer and heart disease data respectively.

Small-scale field evaluation of the efficacy and residual effect of Fludora® Fusion (mixture of clothianidin and deltamethrin) against susceptible and resistant Anopheles gambiae populations from Benin, West Africa.

BACKGROUND: In recognition of the threat of insecticide resistance in vectors of malaria, the WHO Global Malaria Programme recommends the development of an appropriate and comprehensive response to insecticide resistance. In principle, good resistance management practice requires the application of multiple insecticides of different modes of action, for example, in rotations and mixtures. Insecticides recommended by the World Health Organization for indoor residual spraying and long-lasting insecticide nets are limited. It is, therefore, judicious to prevent the rapid spread of insecticide resistance by evaluating new insecticides formulations with different modes of action and long residual effect. METHODS: Fludora® Fusion, a new neonicotinoid IRS formulation (a mixture of 500 g/kg clothianidin and 62.5 g/kg deltamethrin applied 200 mg ai/sqm + 25 mg ai/sqm, respectively) was tested. Small scale field evaluation of this product was conducted in the district of Dangbo in Benin, to compare its efficacy and residual effect on cement and mud walls against those of clothianidin 200 mg ai/sqm (WG 70) alone, and of deltamethrin 25 mg ai/sqm (WG 250) alone. WHO wall cone bioassays were conducted monthly with laboratory susceptible Anopheles "Kisumu" and wild Anopheles gambiae sensu stricto (s.s.) population from Dangbo. The induced mortality by each treatment per wall substrate for 24 h, 48 h, and 72 h post exposure were recorded every month and analysed. RESULTS: Fludora® Fusion and clothianidin WG 70 showed mortality rates over 80% WHO bio-efficacy threshold on cement walls either with susceptible or resistant An. gambiae s.s. over a period of 10 and 9 months, respectively. Treatment with Fludora® Fusion and clothianidin WG 70 on the mud walls showed residual effect for 6 months and 5 months respectively against both susceptible and resistant mosquitoes. During the whole evaluation period, deltamethrin WG 250 showed mortality rates below 80% against resistant Anopheles population. Furthermore, the knock down rates observed with the Fludora® Fusion combination were significantly higher (p < 5%) than those induced by Clothiandin WG 70. CONCLUSION: Both the Fludora® Fusion combination and clothianidin alone showed very good and lasting efficacy for IRS against resistant Anopheles with some residual benefit provided by the combination. The residual efficacy of the Fludora® Fusion combination evaluated at 10 months shows this product is a good candidate for IRS interventions.

Efficacy of a novel mode of action of an indoor residual spraying product, SumiShield® 50WG against susceptible and resistant populations of Anopheles gambiae (s.l.) in Benin, West Africa.

BACKGROUND: Scale-up of the distribution of long-lasting insecticide-treated bed nets and indoor residual spraying with insecticides over the last decade have contributed to the considerable decrease of malaria morbidity and mortality in sub-Saharan Africa. Due to the increasing pyrethroid resistance intensity and the spread of carbamate resistance in Anopheles gambiae (s.s.) mosquitoes and the limited number of insecticides recommended by the WHO for vector control, alternative insecticide formulations for IRS with long-lasting residual activity are required to sustain the gains obtained in most malaria-endemic countries. METHODS: SumiShield 50WG (clothianidin 300 mg ai/m2) developed by Sumitomo Chemical was evaluated alongside deltamethrin 25 mg ai/m2 (K-Othrine 250 WG) against a pyrethroid resistant Anopheles gambiae (s.l.) population in experimental huts in Covè, Benin. Residual activity was also tested in cone bioassays with the susceptible An. gambiae "Kisumu" strain and the local wild resistant population. RESULTS: The results showed very low toxicity from deltamethrin (mortality rates ranged between 1-40%) against host-seeking resistant Anopheles populations. SumiShield in contrast gave an overall mean mortality of 91.7% at the 120 h observation across the eight- month observation period following spraying. The residual activity measured using cone tests was over the 80% WHO threshold for 24 weeks for resistant wild Anopheles population and 32 weeks for the susceptible strain "Kisumu" after the spraying. CONCLUSIONS: SumiShield is a good candidate for IRS in areas of permanent malaria transmission and where Anopheles populations are resistant to other conventional insecticides such as pyrethroids. It would be interesting to complete experimental huts studies by assessing the efficacy and residual effect of SumiShield 50WG at community level (small-scale field testing) in an area where vectors are highly resistant to insecticides.

The influence of particle size on the first flush strength of urban stormwater runoff.

The presence of a first flush (FF) of suspended solids (SS) in stormwater runoff has important implications for the design of treatment facilities, as does the particle size of solids. Whilst numerous studies have examined the FF behaviour of SS, few have disaggregated FF trends by particle size. In this study, the FF behaviour of SS was investigated in five size ranges, sampled from an urban stormwater drainage system located in Dublin, Ireland. A weak FF was exhibited in the gross fraction of SS, with just two events from 14 transporting more than 50% of the SS mass in the first 25% of runoff, implying that treatment structures should be capable of removing SS throughout the storm event. In the majority of rain events, the FF strength increased with decreasing particle size, probably related to the lower intensities required to dislodge solids at the onset of rainfall. Although FF strength was correlated with rain event characteristics, prediction intervals were too broad to confirm FF presence based on rainfall data alone. Therefore, the design of smaller treatment volumes based on an assumption of FF must be justified by local monitoring data.

Caffeine intake is associated with pupil dilation and enhanced accommodation.

PurposeIt is purported that caffeine, an autonomic stimulant, affects visual performance. This study sought to assess whether caffeine intake was associated with changes in pupil size and/or amplitude of accommodation.Patients and methodsA double-masked, crossover study was conducted in 50 healthy subjects of age range 19 to 25 years. Subjects were randomized to treatments such that subjects consumed either 250 mg caffeine drink or vehicle on separate days. Amplitude of accommodation was measured by the push-up technique, and pupil size using a millimeter ruler fixed to a slit lamp biomicroscope in dim illumination (5 lux). Amplitude of accommodation and pupil size were taken at baseline, and at 30, 60 and 90 min time points post treatment. Repeated measures one-way ANOVA and paired t-test were used in analyzing data.ResultsAmplitude of accommodation and pupil size after caffeine intake were significantly greater than vehicle (P<0.001) at each time point. Consumption of the caffeine beverage was associated with significant increases in amplitude of accommodation and pupil size with time (P<0.001). Amplitude of accommodation rose from 12.4 (±2.2 D) at baseline to 15.8(±2.6 D) at 90 min. Similarly, pupil size increased from 3.4 (±0.4 mm) at baseline to 4.5 (±0.72 mm) at 90 min. Consumption of vehicle was not associated with increase in amplitude of accommodation or pupil size with time.ConclusionPupil size and accommodation are affected after ingestion of caffeine. This study suggests caffeine may have some influence on visual functions.

Effect of the approach to insulin therapy on glycaemic fluctuations and autonomic tone in hospitalized patients with diabetes.

AIMS: Glycaemic variability (GV) is associated with mortality in acutely ill patients, but the mechanism is unknown. The objective of this study is to determine whether common approaches to insulin therapy have distinct effects on GV and autonomic tone. METHODS: Hospitalized patients with diabetes were randomized to short-term intravenous (IV) or physiologic subcutaneous (SQ) insulin. Heart rate variability (HRV) and cardiac impedance (pre-ejection period, PEP) were used to estimate parasympathetic and sympathetic tone, respectively. GV was measured using a continuous glucose monitor. RESULTS: Mean glucose tended to be lower initially in the SQ group (N = 16) compared with the IV group (N = 17) on day 1 (10.5 vs. 8.6 mmol/l, p = 0.05), but became non-significant during the transition off of the infusion. There was no difference in glycaemic lability index (GLI), continuous overlapping net glycaemic action (CONGA) or coefficient of variation (CV) on day 1, but by day 2, these measures were higher in the IV group (p < 0.05 for all). PEP was higher in the SQ group during (110 vs. 123 ms, p = 0.02) and after the intervention (104 vs. 126 ms, p = 0.004). Hypoglycaemia was similar in both groups. There were only small differences in HRV. Post-treatment PEP was inversely correlated with log GLI (r = -0.41, p = 0.03) but not other measures. CONCLUSIONS: Short-term IV insulin is associated with an increase in multiple GV measures compared with optimal SQ insulin. However, GLI was the only predictor of PEP. Further research is needed to determine if interventions that minimize GV improve outcomes in the hospital.

Use of Moringa oleifera seed extracts to reduce helminth egg numbers and turbidity in irrigation water.

Water from wastewater-polluted streams and dug-outs is the most commonly used water source for irrigation in urban farming in Ghana, but helminth parasite eggs in the water represent health risks when used for crop production. Conventional water treatment is expensive, requires advanced technology and often breaks down in less developed countries so low cost interventions are needed. Field and laboratory based trials were carried out in order to investigate the effect of the natural coagulant Moringa oleifera (MO) seed extracts in reducing helminh eggs and turbidity in irrigation water, turbid water, wastewater and tap water. In medium to high turbid water MO extracts were effective in reducing the number of helminth eggs by 94-99.5% to 1-2 eggs per litre and the turbidity to 7-11 NTU which is an 85-96% reduction. MO is readily available in many tropical countries and can be used by farmers to treat high turbid water for irrigation, however, additional improvements of water quality, e.g. by sand filtration, is suggested to meet the guideline value of ≤ 1 helminth egg per litre and a turbidity of ≤ 2 NTU as recommended by the World Health Organization and the U.S. Environmental Protection Agency for water intended for irrigation. A positive correlation was established between reduction in turbidity and helminth eggs in irrigation water, turbid water and wastewater treated with MO. This indicates that helminth eggs attach to suspended particles and/or flocs facilitated by MO in the water, and that turbidity and helminth eggs are reduced with the settling flocs. However, more experiments with water samples containing naturally occurring helminth eggs are needed to establish whether turbidity can be used as a proxy for helminth eggs.

Differential response between diabetes and stress-induced hyperglycaemia to algorithmic use of detemir and flexible mealtime aspart among stable postcardiac surgery patients requiring intravenous insulin.

AIM: To determine whether an insulin algorithm could be used in a similar manner in the setting of diabetes and stress hyperglycaemia following cessation of intravenous (IV) insulin after cardiac surgery. METHODS: Subjects who were clinically stable, requiring ≥ 1 unit/h of IV insulin 48 h after surgery, were randomized to once daily detemir at 50, 65 or 80% of IV insulin requirements and received aspart according to carbohydrate intake. Diabetes was defined as any history of diabetes or preoperative HbA1c 6.5%. RESULTS: The morning glucose in patients with diabetes was 143 mg/dl (n = 61) vs. 124 mg/dl in those with stress hyperglycaemia (n = 21,p = 0.05) on day 1 and 127 vs. 110 mg/dl over 72 h (p = 0.01). This was unaffected by adjustment for initial dosing group. At 72 h, 56% of patients with stress hyperglycaemia reached AM (80-130 mg/dl) and 87% reached overall (80-180 mg/dl) glucose targets, compared to 90 and 100% of patients with stress hyperglycaemia, respectively. There was no difference in hypoglycaemia in patients with stress hyperglycaemia or diabetes. The percentage of patients with diabetes receiving insulin was 46% on admission and 77% at discharge, compared to 0 and 42% of patients with stress hyperglycaemia. CONCLUSIONS: Following cardiac surgery, patients with stress hyperglycaemia may be converted from IV insulin to detemir with a 50% conversion factor, while patients with diabetes may require a higher conversion factor. Stress hyperglycaemia may be prolonged; the intensity and duration of insulin therapy required for optimal outcomes warrants further examination.

Pelvic organ prolapse in rural Ghana.

OBJECTIVE: To determine the prevalence of pelvic organ prolapse (POP) and its impact on the lives of women in Sekyidumasi, a rural Ghanaian community. METHODS: A cross-sectional study of 200 women was performed using a questionnaire and pelvic examination to detect symptoms and signs of prolapse. Main outcome measures were the presence of POP and its impact on quality of life. RESULTS: Out of 174 women included in the study, 21 women (12.07%) had POP. Seventeen of these women (81%) were symptomatic, of which only 6 women (35.3%) had sought treatment because of financial constraints. The odds of prolapse increased with increasing parity (P=0.02) and age (P<0.01). The main impacts of prolapse were on emotional well-being (52.4%), the women's relationship with their partner (46.2%), and sex life (25%). CONCLUSION: Only about one-third of women with symptomatic prolapse sought treatment because the cost of medical care outweighed the impact of the condition on their lives.

Effect on glycemic control of the addition of 2.5 mg glipizide GITS to metformin in patients with T2DM.

AIMS: This study evaluated the effects on glycemic control of the addition of 2.5 mg glipizide GITS to metformin in patients with mild-to-moderate, but suboptimally controlled type 2 diabetes. METHODS: In this multicenter, double-blind, placebo-controlled study, 122 patients with type 2 diabetes inadequately controlled (A1c 7-8.5%) on metformin (> or =1000 mg/day for > or =3 months) were randomized to 16 weeks treatment with 2.5 mg/day glipizide GITS (n=61) or placebo (n=61), in addition to their current metformin dose. The primary efficacy variable was the change in A1c from baseline to endpoint. Changes in fasting plasma glucose (FPG), insulin concentrations, lipid profile and safety variables were also measured. RESULTS: The addition of glipizide GITS to metformin gave significantly greater improvements in mean A1c and FPG from baseline to endpoint than placebo addition (p<0.0002). Significantly more patients in the glipizide GITS group than in the placebo group achieved the target A1c level of A1c<7.0% (p<0.0001) and an A1c<6.5% (p<0.0033). Fasting insulin concentrations were similar in both groups and unchanged by treatment. Addition of glipizide GITS to metformin did not produce any significant or clinically relevant weight gain or changes in BMI. Both treatment regimens were well tolerated. CONCLUSIONS: This study showed that the addition of 2.5 mg glipizide GITS to metformin significantly improved glucose control in patients with type 2 diabetes inadequately controlled by metformin monotherapy.

Long term cardiovascular effects of oral antidiabetic agents in non-diabetic patients with insulin resistance: double blind, prospective, randomised study.

OBJECTIVE: To study the long term cardiovascular effects of oral antidiabetic agents in non-diabetic patients with insulin resistance. PATIENTS: 181 African American subjects with insulin resistance and normal glucose tolerance test were randomised to receive glipizide 5 mg/day (n = 25), metformin 500 mg/day (n = 59), or placebo (n = 97) for 24 months. Insulin sensitivity, glucose tolerance, lipid profile, left ventricular mass (echocardiography), aortic distensibility (echocardiography, blood pressure), aortic pulse wave velocity (PWV, carotid to femoral artery, Doppler) were measured at baseline and at 12 and 24 months after randomisation. RESULTS: A significant increase in PWV was observed in both glipizide (mean (SEM) change at 24 months 2.8 (2.7) m/s, p = 0.012) and metformin (2.2 (0.7) m/s, p = 0.01) groups during the follow up period. In contrast, PWV remained unchanged in the placebo group. The increase in PWV in the treatment groups was significant compared with placebo (analysis of variance p < 0.05). Other cardiovascular or metabolic variables did not change significantly compared with placebo during follow up. CONCLUSIONS: The observed increase in PWV is consistent with a decrease in the elastic properties of the aorta. The use of oral antidiabetic agents for the prevention of cardiovascular complications in non-diabetic African Americans with insulin resistance needs to be critically evaluated.

The impact of an insulin sensitizer, troglitazone, on glucose metabolism in African Americans at risk for type 2 diabetes mellitus: a placebo-controlled, 24-month randomized study.

African Americans (AA) have greater prevalence of type 2 diabetes mellitus (DM), and nondiabetic AA have demonstrated increased insulin resistance when compared with Caucasian Americans (CA). The objective of this study was to examine the impact of chronic use of an insulin sensitizer on glucose metabolism in normal glucose tolerant AA at risk for DM (previous gestational diabetes mellitus [GDM] or first-degree relative with DM). Forty-nine high-risk AA received 200 mg/d troglitazone (TRO) versus 81 age-, weight-, and body mass index (BMI)-matched high-risk AA who received placebo (PLA) for 24 months. Yearly anthropometric measurements, oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test (FSIVGTT) were performed. Biochemical parameters were monitored quarterly. There was no significant change in anthropometric measurements over 24 months in TRO versus PLA. There were no significant differences in serum glucose, insulin, or C-peptide incremental area under the curve (AUC) in TRO versus PLA at baseline or 24 months for OGTT and FSIVGTT. The insulin sensitivity (S(I)) for TRO and PLA increased from baseline to 24 months by 17% and 16%, respectively. The TRO demonstrated a 26% increase in insulin/glucose ratio versus 1% increase in the PLA at 24 months. The disposition index (DI) increased 33% from baseline in TRO versus 21% increase in PLA. Modest improvement in glucose metabolism was seen in TRO when compared with PLA. TRO was well tolerated without significant reported adverse events. Based on our current data, the treatment of normal glucose tolerant high-risk AA with thiazolidinedione (TZD) may be beneficial to "reset" and protect glucose metabolism by improving insulin responses. Because of the potential drug-related risks associated with use of TZD and the proven positive impact of diet and exercise in prevention of DM, studies of longer duration with examination of other potentially beneficial parameters, such as cardiovascular indices and inflammatory markers will be necessary to justify the cost in the nondiabetic population.

Insulin sensitivity and cardiovascular risk factors in hypertensive and normotensive native Ghanaians.

AIMS/HYPOTHESIS: The objective of this study was to examine the relationships among insulin and insulin sensitivity and risk factors for cardiovascular diseases in native Ghanaians with and without hypertension. METHODS: We measured the anthropometric parameters, systolic and diastolic blood pressure, fasting serum triglycerides, cholesterol and high-density lipoprotein cholesterol and fasting and stimulated glucose, insulin and C-peptide of 200 Ghanaian subjects, who were between 25 to 74 years of age, and residing in the Accra Metropolitan area. Serum glucose, C-peptide and insulin concentrations were measured at baseline (fasting) and also 2 h after 75 gm oral glucose drink. Homeostasis model assessment was used to measure insulin resistance. Hypertension was defined as a blood pressure higher than 140/90 mmHg. RESULTS: There were 53 subjects with hypertension (HBP) and 147 subjects with normal blood pressure (NBP). The mean BMI, waist circumference and waist-to-hip circumference ratio for HBP and NBP subjects were 27.4+/-0.8, 24.8+/-0.4 kg/m(2); 89.8+/-11.7, 81.1+/-0.9 cm; and 0.87+/-0.08, 0.82+/-0.08 respectively, (p<0.05). The fasting and 2-h plasma glucose concentrations in HBP and NBP subjects were 5.5+/-0.2, 7.2+/-0.3 mmol/l and 5.2+/-01, 6.8+/-0.2 mmol/l respectively (p>0.05). The corresponding fasting and 2-h insulin concentrations were 10.0+/-0.7, 8.0+/-0.4 uU/ml and 47.3+/-3.7, 37.3+/-2.5 uU/ml respectively (p<0.05). The insulin resistance index (HOMA-IR) in the HBP and the NBP groups were 2.49+/-0.2 and 1.95+/-0.13 (p<0.05). The two groups had similar fasting and stimulated C-peptide, lipids and HDL concentrations. Correlations were found between blood pressure and the concentrations of lipids, HDL, fasting and stimulated insulin and C-peptide, and between fasting insulin and HOMA-IR with lipids and HDL concentrations. On multiple regression analysis, fasting insulin and HOMA-IR did not influence blood pressure variations significantly. CONCLUSIONS/INTERPRETATION: We found clustering of hyperinsulinaemia, insulin resistance and truncal obesity in hypertensive Ghanaian subjects but dissociation between insulin resistance, hypertension and atherogenic lipid and lipoprotein profile.

Minimal model analyses of beta cell secretion, insulin sensitivity and glucose effectiveness in glucose tolerant, non-diabetic first-degree relatives of Ghanaian patients with type 2 diabetes and healthy control subjects.

OBJECTIVE: We have examined the importance of positive family history of type 2 diabetes on serum glucose, insulin sensitivity, and beta cell secretion in native West Africans (Ghanaians) who reside in their native country. RESEARCH AND METHODS: We evaluated the beta cell secretion, insulin secretion, insulin sensitivity (Si), and glucose effectiveness (Sg) in 42 healthy non-diabetic first-degree relatives of Ghanaian patients with type 2 diabetes (26 females and 16 males) and in 22 healthy control subjects without a family history of type 2 diabetes (12 females and 10 males) living in Accra, Ghana, West Africa. A standard oral glucose tolerance test (OGTT) and a frequently sampled intravenous glucose tolerance (FSIGT) test were performed in each subject. Si and Sg were measured using Bergman's minimal model method. RESULTS: During oral glucose challenge, fasting and postprandial serum glucose levels were not significantly different between the relatives and healthy controls. Mean serum insulin and c-peptide responses after oral glucose tolerance test at t = 60, 90 and 120 minutes (P<.05) were significantly greater in the relatives than in the healthy controls. During the FSIGT, the mean serum glucose responses did not differ. Mean total and acute first and second phases of serum insulin and c-peptide responses were greater in the relatives than in the healthy controls. We found that the Si tended to be lower in the relatives than in the controls, but the mean difference did not vary significantly between the two groups. In addition, the glucose effectiveness at basal insulin level (Sg) was not significantly different in the relatives and healthy controls. CONCLUSIONS: The present study demonstrates that hyperinsulinemia and a tendency to lower insulin sensitivity (insulin resistance), but not altered glucose effectiveness, are found in healthy non-diabetic, first-degree relatives of Ghanaian patients with type 2 diabetes as compared to healthy subjects living in their native country. We conclude that genetic factors could play a significant role in the development of type 2 diabetes in indigenous Ghanaians residing in their native country.