Department of Physiology
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Item Sickle Cell Disease: Reappraisal of the Role of Foetal Haemoglobin Levels in the Frequency of Vaso-Occlusive Crisis(Ghana Medical Journal, 2015-06) Antwi-Boasiako, C.; Frimpong, E.; Ababio, G.K.; Dzudzor, B.; Ekem, I.; Gyan, B.; Sodzi-Tettey, N.A.; Antwi, D.A.Background: Foetal haemoglobin has been implicated in the modulation of sickle cell crisis. Its level is generally inversely proportional to the severity of sickle cell disease (SCD) for a given sickle cell phenotypes. The main aim of therapy for vaso-occlusive crisis (VOC), which is the hallmark of SCD, is to reduce the chances of sickling through the prevention of polymerization of HbS. One way of preventing this polymerization is by increasing foetal haemoglobin levels. Objectives: To determine the relationship between HbF levels and the frequency of crisis in SCD patients in Ghana. Method: A longitudinal retrospective survey covering a period of 30 months was carried out on adult SCD patients at the Sickle Cell Clinic of the Korle-Bu Teaching Hospital. Results: Eighty-three adults aged 15 to 65 years made up of 40 males and 43 femalea were studied. Analysis of variance (ANOVA) gave significant results in Hb and HbF levels. Higher HbF levels were positively related to less frequent crisis and were significantly high in SCD patients than in controls. HbF effects on the clinical manifestations on SCD were variable. Conclusion: Threshold values of HbF play a role in reducing the frequency of vaso-occlusive crisis in SCD patients and this finding contributes to the body of available literature on SCD severity. However our work does not give the apparent threshold level of helpful HBF Level in SCD.Item Arterial Stiffness in Nonhypertensive Type 2 Diabetes Patients in Ghana(International Journal of Endocrinology, 2016) Yeboah, K.; Antwi, D.A.; Gyan, B.Background. Increased arterial stiffness is an independent cardiovascular risk factor in diabetes patients and general population. However, the contribution of diabetes to arterial stiffness is often masked by coexistent obesity and hypertension. In this study, we assessed arterial stiffness in nonhypertensive, nonobese type 2 diabetes (T2DM) patients in Ghana. Methods. In case-control design, 166 nonhypertensive, nonobese participants, comprising 96 T2DM patients and 70 nondiabetes controls, were recruited. Peripheral and central blood pressure (BP) indices were measured, and arterial stiffness was assessed as aortic pulse wave velocity (PWVao), augmentation index (AIx), cardioankle vascular index (CAVI), and heart-ankle pulse wave velocity (haPWV). Results. With similar peripheral and central BP indices, T2DM patients had higher PWVao (8.3 � 1 versus 7.8 � 1.3, p = 0.044) and CAVI (7.9 � 1.2 versus 6.9 � 0.7, p = 0.021) than nondiabetic control. AIx and haPWV were similar between T2DM and nondiabetic controls. Multiple regression models showed that, in the entire study participants, the major determinants of PWVao were diabetes status, age, gender, systolic BP, and previous smoking status (β = 0.22, 0.36, 0.48, 0.21, and 0.25, resp.; all p < 0.05); the determinants of CAVI were diabetes status, age, BMI, heart rate, HbA1c, total cholesterol, HDL cholesterol, and previous smoking status (β = 0.21, 0.38, 0.2, 0.18, 0.24. 0.2, -0.19, and 0.2, resp.; all p < 0.05). Conclusion. Our findings suggest that nonhypertensive, nonobese T2DM patients have increased arterial stiffness without appreciable increase in peripheral and central pressure indices. � 2016 Kwame Yeboah et al.Item Peripheral sensory neuropathy in type 2 diabetes patients: A case control study in Accra, Ghana(Journal of Clinical and Translational Endocrinology, 2016-09) Yeboah, K.; Puplampu, P.; Boima, V.; Antwi, D.A.; Gyan, B.; Amoah, A.G.B.Objective Peripheral sensory neuropathy (PSN) is a common cause of ulceration and amputation in diabetes (DM) patients. The prevalence of PSN in DM patients is largely undetermined in sub-Saharan African population. We studied the burden of PSN in DM patients using a validated questionnaire and quantitative sensory test. Methods In a case-control design, PSN was measured in 491 DM patients and 330 non-DM controls using Michigan neuropathy screening instrument (MNSI) and vibration perception threshold (VPT). PSN was defined as MNSI symptom score ≥7, MNSI examination score ≥2 or VPT ≥25V. Results The prevalence of PSN screened by MNSI symptom score, MNSI examination score and VPT was 7.1%, 51.5% and 24.5% in DM patients; and 1.5%, 24.5% and 8.5% in non-DM participants respectively. The major determinants of PSN screened by MNSI examination score were diabetes status [OR (95% CI): 4.31 (2.94–6.31), p < 0.001], age [1.03 (1.01–1.05), p < 0.001], previous [4.55 (2.11–9.82), p < 0.001] and current [8.16 (3.77–17.68), p < 0.001] smoking status. The major determinants of PSN screened by VPT were diabetes status [1.04 (1.02–1.06), p < 0.001], age [1.02 (1.01–1.03), p = 0.047], heart rate [1.78 (1.08–2.92), p = 0.023], second-hand smoking [3.66 (2.26–5.95), p < 0.001] and body height [3.28 (1.65–8.42), p = 0.015]. Conclusion Our study has shown high burden of PSN in DM patients in Ghana using simple, accurate, and non-invasive screening tools like MNSI and neurothesiometer. © 2016Item Sickle Cell Disease: Reappraisal of the Role of Foetal Haemoglobin Levels in the Frequency of Vaso-Occlusive Crisis(Ghana Medical Journal, 2015-06) Antwi-Boasiako, C.; Frimpong, E.; Ababio, G.K.; Dzudzor, B.; Ekem, I.; Gyan, B.; Sodzi-Tettey, N.A.; Antwi, D.A.Foetal haemoglobin has been implicated in the modulation of sickle cell crisis. Its level is generally inversely proportional to the severity of sickle cell disease (SCD) for a given sickle cell phenotypes. The main aim of therapy for vaso-occlusive crisis (VOC), which is the hallmark of SCD, is to reduce the chances of sickling through the prevention of polymerization of HbS. One way of preventing this polymerization is by increasing foetal haemoglobin levels. To determine the relationship between HbF levels and the frequency of crisis in SCD patients in Ghana. A longitudinal retrospective survey covering a period of 30 months was carried out on adult SCD patients at the Sickle Cell Clinic of the Korle-Bu Teaching Hospital. Eighty-three adults aged 15 to 65 years made up of 40 males and 43 femalea were studied. Analysis of variance (ANOVA) gave significant results in Hb and HbF levels. Higher HbF levels were positively related to less frequent crisis and were significantly high in SCD patients than in controls. HbF effects on the clinical manifestations on SCD were variable. Threshold values of HbF play a role in reducing the frequency of vaso-occlusive crisis in SCD patients and this finding contributes to the body of available literature on SCD severity. However our work does not give the apparent threshold level of helpful HBF Level in SCD. (PDF) Sickle Cell Disease: Reappraisal of the Role of Foetal Haemoglobin Levels in the Frequency of Vaso-Occlusive Crisis. Available from: https://www.researchgate.net/publication/281160890_Sickle_Cell_Disease_Reappraisal_of_the_Role_of_Foetal_Haemoglobin_Levels_in_the_Frequency_of_Vaso-Occlusive_Crisis [accessed Sep 18 2018].Item Nitric oxide dysregulation in the pathogenesis of preeclampsia among Ghanaian women(Dove Press Journal: Integrated Blood Pressure Control, 2015-02-19) Adu-Bonsaffoh, K.; Antwi, D.A.; Amenyi, S.O.; Gyan, B.Background: Preeclampsia (PE) is still a disease of theories as the exact cause remains uncertain. Widespread vascular endothelial cell dysfunction is thought to mediate the generalized vasospasm and hypertension characteristic of PE. Altered nitric oxide (NO) production has been associated with the endothelial dysfunction in the pathogenesis of PE but conflicting results have emerged from previous studies. Objectives: To determine maternal serum levels of NO, a biomarker of endothelial function, in nonpregnant, normal pregnant, and preeclamptic women. Materials and methods: This was a cross-sectional case–control study of 277 women comprising 75 nonpregnant, 102 normal pregnant, and 100 preeclamptic women conducted at the Korle Bu Teaching Hospital between April and June 2011. About 5 mL of venous blood was obtained from the participants for the various investigations after meeting the inclusion criteria and signing to a written consent. Serum levels of NO were determined by Griess reaction. The data obtained were analyzed with SPSS version 20. Results: The study showed significantly elevated serum levels of NO in preeclamptic women (82.45±50.31 μM) compared with normal pregnant (33.12±17.81 μM) and nonpregnant (16.92±11.41 μM) women with P,0.001. The alteration in maternal serum NO levels was significantly more profound in early-onset (severe) PE (119.63±45.860 μM) compared to that of late-onset (mild) disease (62.44±40.44 μM) with P0.001, indicating a more severe vascular endothelial cell dysfunction in the early-onset disease. Conclusion: This study has determined a profound NO upregulation in PE evidenced by significant elevation of NO metabolite levels compared to normal pregnancy. This might be due to deranged endothelial function with dysregulated production of NO to restore the persistent hypertension characteristic of PE.Item Body composition and ankle-brachial index in Ghanaians with asymptomatic peripheral arterial disease in a tertiary hospital(2016-05-13) Yeboah, K.; Puplampu, P.; Yorke, E.; Antwi, D.A.; Gyan, B.; Amoah, A.G.B.Abstract Background Ankle-brachial index (ABI) and indices of obesity are both use to indicate cardiovascular risk. However, association between body composition indices and ABI, a measure of peripheral arterial disease, is inconsistent in various study reports. In this study, we investigated the relationship between ABI and general and central indices of obesity in Ghanaians without history of cardiovascular diseases. Method In a case–control design, ABI was measured in a total of 623 subjects and categorised into PAD (ABI ≤ 0.9, n = 261) and non-PAD (ABI > 0.9, n = 362) groups. Anthropometric indices, BMI, waist circumference (WC), waist-hip ratio (WHR) and waist-height ratio (WHtR) were also measured. Results PAD subjects had higher mean BMI (29.8 ± 8.7 vs. 26.5 ± 7.6 kg/m2, p = 0.043) and waist circumference (95 ± 15 vs. 92 ± 24 cm, p = 0.034) than non-PAD subjects. In multivariable logistic regression models, having BMI ≥ 30 kg/m2 increased the odds of both unilateral [OR (95 % CI): 2 (1.14–3.51), p < 0.01] and overall PAD [2 (1.22–3.27), p < 0.01]. Conclusion In indigenous Ghanaians in our study, PAD participants had higher BMI and waist circumference than non-PAD participants. Also, halving BMI ≥ 30 kg/m2 was associated with twofold increase in the odds of PAD.Item Brain regulation of appetite and satiety(2008-12) Ahima, R.S.; Antwi, D.A.Interest in the control of feeding has increased as a result of the obesity epidemic and rising incidence of metabolic diseases. The brain detects alterations in energy stores and triggers metabolic and behavioral responses designed to maintain energy balance. Energy homeostasis is controlled mainly by neuronal circuits in the hypothalamus and brainstem, whereas reward and motivation aspects of eating behavior are controlled by neurons in limbic regions and the cerebral cortex. This article provides an integrated perspective on how metabolic signals emanating from the gastrointestinal tract, adipose tissue, and other peripheral organs target the brain to regulate feeding, energy expenditure, and hormones. The pathogenesis and treatment of obesity and abnormalities of glucose and lipid metabolism are discussed.Item Comparative study of two Kalanchoe species: Total flavonoid and phenolic contents and antioxidant properties(2012) Asiedu-Gyekye, I.J.; Antwi, D.A.; Bugyei, K.A.; Awortwe, C.Item Determination of the vibration perception threshold (VPT) in adult non-diabetic Ghanaians using a Neurothesiometer(2012) Djankpa, F.T.; Adzaku, F.K.; Osunuga, A.; Amoah, A.G.B.; Antwi, D.A.; Osunuga, O. A.; Amoah, S.K.Item Some effects of the medicinal plant kalanchoe pinnata.(2002) Isaac, J.A.; Antwi, D.A.; Tete-DonkorThe hepatoprotective and choleretic effects of Kalanchoe pinnata syrup prepared from its extract were studied using the rat model of toxic hepatitis, produced by the administration of the hepatotoxic compound 50% solution of carbon tetrachloride. The syrup was introduced in a dosage of 30 mg/kg. After the administration of syrup Kalanchoe (per os) in rats with toxic hepatitis, the following enzymes considered to be informative during toxic hepatitis were determined: alanine transaminase, alkaline phosphatase and triglycerides. The cholagogic (choleretic) effect was determined by cannulating the common bile duct and determining the amount and content of bile produced within three hours. The antimicrobial activity of the syrup was determined using a microbial inhibition assay. The Kalanchoe syrup was seen to normalize the level of alaninetransaminase, alkaline phosphatase and triglycerides in the animals with toxic hepatitis and increase the secretion of bile with the contents of cholesterine. Acids and the cholato-cholesteric coefficient in the bile remained unchanged. The syrup was found to react with some strains of Staphylococcus aureus and Escherchia coli. This finding demonstrates the hepatoprotective, choleretic and antimicrobial activity of syrup Kalanchoe.