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Biomedical subjects

Z A Gomo

Publications and source records attributed to Z A Gomo.

At least 19 recordsLinked to original sources
PubMed2001

Association of pulmonary tuberculosis with increased dietary iron.

To determine whether increased dietary iron could be a risk factor for active tuberculosis, dietary iron history and human immunodeficiency virus (HIV) status were studied in 98 patients with pulmonary tuberculosis and in 98 control subjects from rural Zimbabwe. Exposure to high levels of dietary iron in the form of traditional beer is associated with increased iron stores in rural Africans. HIV seropositivity was associated with a 17.3-fold increase in the estimated odds of developing active tuberculosis (95% confidence interval [95% CI], 7.4-40.6; P<.001), and increased dietary iron was associated with a 3.5-fold increase (95% CI, 1.4-8.9; P=.009). Among patients treated for tuberculosis, HIV seropositivity was associated with a 3.8-fold increase in the estimated hazard ratio of death (95% CI, 1.0-13.8; P=.046), and increased dietary iron was associated with a 1.3-fold increase (95% CI, 0.4-6.4; P=.2). These findings are consistent with the hypothesis that elevated dietary iron may increase the risk of active pulmonary tuberculosis.

Adult↗
PubMed2001

Clinical and genetic heterogeneity in hereditary haemochromatosis: association between lymphocyte counts and expression of iron overload.

To identify a new marker of expression of disease, independent of HFE genotype in patients with hereditary haemochromatosis (HHC), the total peripheral blood lymphocyte counts were analysed according to iron status in two groups of subjects with HFE mutations. The groups consisted of 38 homozygotes for C282Y, and 107 heterozygotes for the C282Y or compound heterozygotes for C282Y and H63D. For control purposes, total lymphocyte counts and iron status were also examined in 20 index patients with African dietary iron overload, a condition not associated with HFE mutations, and in 144 members of their families and communities. Mean lymphocyte numbers were lower in C282Y homozygous HHC index subjects with cirrhosis and higher iron stores than in those without cirrhosis and with lower iron burdens [(1.65 +/- 0.43) x 10(6)/mL vs. (2.27 +/- 0.49) x 10(6)/mL; p = 0.008]. Similarly, mean lymphocyte counts were significantly lower in C282Y heterozygotes and C282Y/H63D compound heterozygotes with iron overload and increased serum ferritin concentrations compared to those with normal serum ferritin concentrations (p < 0.05). Statistically significant negative correlations were found, in males, between lymphocyte counts and the total body iron stores, either in C282Y homozygous HHC patients (p = 0.031 in a multiple regression model dependent on age) and in C282Y heterozygotes or C282Y/H63D compound heterozygotes with iron overload (p = 0.029 in a simple linear model). In contrast, lymphocyte counts increased with increasing serum ferritin concentrations among the index subjects with African iron overload (r = 0.324, not statistically significant) and among the members of their families and communities (r = 0.170, p = 0.042). These results suggest that a lower peripheral blood lymphocyte count is associated with a greater degree of iron loading in HFE haemochromatosis but not in African iron overload, and they support the notion that the lymphocyte count may serve as a marker of a non-HFE gene that influences the clinical expression of HFE haemochromatosis.

Adult↗
PubMed2001

Carbohydrate-deficient transferrin and chronic alcohol ingestion in subjects with transferrin CD-variants.

Carbohydrate-deficient transferrin (CDT) is widely accepted as screening test for excessive alcohol consumption. However, results from subjects with transferrin variants must be interpreted with caution since chromatography-based methods may give false-positive results. Furthermore, due to the co-elution in HPLC or the co-migration in capillary zone electrophoresis (CZE) of the di- and trisialylated C transferrins with the tetrasialylated D peak, exact measurement of CDT is impossible in CD-variants. Therefore, in this study, we tried to offer a different solution, including only the asialo-D, asialo-C, monosialo-D, monosialo-C, disialo-D and trisialo-D transferrins in the CDT calculation and referring to a different cut-off value for CDT in transferrin CD-variants. Comparison of alcohol consumers with teetotalers demonstrated area under the receiver operating characteristic curve of 0.79 and 0.76 for carbohydrate-deficient transferrin, 0.71 and 0.71 for mean corpuscular volume and 0.51 and 0.68 for gamma-glutamyltransferase in 43 subjects with transferrin CD-variants and 225 subjects with CC-phenotypes, respectively. Since false-positive carbohydrate-deficient transferrin results due to a transferrin CD-variant have major social implications, capillary electrophoresis-based or similar methods (HPLC, FPLC) should be preferred in populations carrying a high D-allele frequency.

Adult↗
PubMed2000

Reference range of serum haptoglobin is haptoglobin phenotype-dependent in blacks.

Reference values for serum haptoglobin (Hp), were established in a Black Zimbabwean population. The upper limit (2.15 g/l) is comparable to the one in Caucasians, but the lower limit (0.12 g/l) is much lower than the proposed interim international reference limit (0.3 g/l). Subjects that typed as Hp 0-0 by starch gel electrophoresis technique were retyped using high performance gel permeation chromatography. This resulted in a 32% decrease in the frequency of Hp 0-0, but an increase in Hp 2-2 and Hp 2-1M phenotype frequencies. In the Zimbabwean Blacks, the Hp 0-0 frequency was estimated to be 2.9%. Haptoglobin reference values were found to be Hp phenotype-dependent; highest values were found in Hp 1-1 (median 0.88 g/l; range 0.31-1.69 g/l) and in Hp 2-1 (median 0.90 g/l; range 0.31-2.22 g/l) and lower values (median 0.66 g/l; range 0.13-1.79 g/l) in Hp 2-2 subjects. The Hp 2-1M phenotype was characterized by low reference values (0.18-1.25 g/l) (P<0.05). In three cases of the rare variant Hp Johnson, high Hp concentrations were found (median 1. 57 g/l; range 0.98-1.57 g/l).

Adult↗
PubMed2000

Haptoglobin polymorphism and mortality in patients with tuberculosis.

SETTING: A rural Zimbabwean hospital and the surrounding community. OBJECTIVES: To determine whether a particular haptoglobin phenotype is associated with increased susceptibility to clinical pulmonary tuberculosis, and to determine the outcome of treatment for pulmonary tuberculosis according to haptoglobin phenotype. DESIGN: A case-control study, and a prospective cohort study. RESULTS: We studied 98 consecutive patients with sputum-positive pulmonary tuberculosis and 98 sex- and age-matched controls. The haptoglobin (Hp) phenotype distributions did not differ significantly between the tuberculosis patients and controls (P = 0.5). During the 18-month follow-up period after the start of tuberculosis treatment, 6/18 (33%) cases with Hp 2-2 phenotype died compared to 9/47 (19%) with Hp 2-1 and 3/31 (10%) with Hp 1-1. In a logistic regression model, the odds of dying were 6.1-fold greater with Hp 2-2 than with Hp 1-1 (95%CI 1.04-35.1, P = 0.04). CONCLUSION: Our results suggest that there is equal susceptibility to clinical pulmonary tuberculosis disease amongst different haptoglobin phenotypes. Nonetheless, tuberculosis patients with Hp 2-2 phenotype had a higher risk of mortality.

Adult↗
PubMed2000

Transferrin polymorphism influences iron status in blacks.

BACKGROUND: Genetic variants of human transferrin (TF) have been described, but little is known about their functional differences. We studied iron status according to TF phenotype in a healthy Zimbabwean population and in subjects at risk of African iron overload. METHODS: The study population consisted of 483 nondrinkers, 31 drinking spouse pairs, and 5 family pedigrees (n = 88) with index cases of iron overload. TF phenotypes were determined using starch gel electrophoresis. To evaluate iron status, serum iron, total iron-binding capacity (TIBC), ferritin, and soluble TF receptors were measured, and the percentage of saturation and the serum iron:TF ratio were calculated. The binding of the TF variants was studied by equilibrium dialysis. RESULTS: The reference population was characterized by a high TF D allele frequency (0.050) and a complete absence of homozygous TF DD individuals. Similar allele frequencies were observed in subjects at risk of African iron overload. In the reference population, male TF CD heterozygotes had significantly lower (P <0.01) values for serum iron, TIBC, TF saturation, and serum iron:TF ratio than the TF CC homozygotes; in females, only TIBC was significantly different. Overall red blood cell indices did not differ according to TF phenotype. In the population at risk of African iron overload, only serum iron:TF ratio was consistently significantly lower in TF CD phenotypes (P <0.05). After equilibrium dialysis, the amount of iron bound by TF was significantly lower (P <0.01) in TF CD individuals. CONCLUSIONS: The present data demonstrate a functional difference between TF phenotypes in blacks.

Adult↗
PubMed1999

A traditional beverage prevents iron deficiency in African women of child bearing age.

OBJECTIVE: To determine if a traditional item in the diet might be useful in preventing iron deficiency in African women of child-bearing age. DESIGN: In a prospective study, the iron status of women who did and did not drink traditional beer high in iron and folic acid, was compared. Iron status was determined by a combination of haemoglobin, serum ferritin and transferrin saturation. SETTING: The study was conducted amongst rural villagers in the Murehwa and Zaka districts of Zimbabwe and in Mpumalanga Province, South Africa. SUBJECTS: 112 women aged between 12 and 50 y from a population of 425 rural people participating in on-going family genetic studies. RESULTS: Women who consumed traditional beer had significantly higher serum ferritin concentrations and transferrin saturations compared to non-drinkers (P = 0.0001 and 0.03 respectively). Iron deficiency anaemia was not present in drinkers but the prevalence in non-drinkers was 13%. Forty seven percent of the non-drinkers and only 14% of the drinkers had evidence of iron deficiency (P = 0.002). Six (21%) of the drinkers and none of the non-drinkers had evidence of iron overload (transferrin saturation > 55% and serum ferritin > 400 ug/l). CONCLUSION: We conclude that the consumption of traditional beer, rich in iron, protects women against iron deficiency. While the use of an alcoholic beverage is not ideal, our findings suggest that indigenous cultural practices might be successfully employed or adapted for promoting iron nutrition.

Adolescent↗
PubMed1999

Urinary iodine concentrations and thyroid function in adult Zimbabweans during a period of transition in iodine status.

BACKGROUND: In 1993 the compulsory iodization of salt was introduced in Zimbabwe, a country that was previously an area of severe iodine deficiency. OBJECTIVE: The objective of this study was to document urinary iodine excretion and biochemical thyroid function in seemingly healthy, community-dwelling adults after the introduction of iodization. DESIGN: A multistage, random sampling method was used in rural and urban settings to identify households from which the senior household member (aged >35 y) was recruited (alternating male and female recruits). Demographic data were collected for each subject and urinary and venous blood samples were taken. Urinary iodine excretion and serum thyroid hormone status (thyrotropin and total thyroxin) were evaluated according to age, sex, and area of residence. RESULTS: A total of 736 adults were recruited (253 men; mean age: 64 y). Urinary iodine concentrations were high [median (first and third quartiles): 4.41 (2.84, 6.78) micromol/L, or 560 (360, 860) microgram/L] and were significantly higher in rural areas than in urban areas [4.73 (3.07, 7.14) micromol/L, or 600 (390, 906) microgram/L, compared with 3.47 (2.05, 4.73) micromol/L, or 440 (260, 600) microgram/L; P < 0.001]. Urinary iodine excretion declined significantly with increasing age (r = -0.29, P < 0.001). Serum thyroid status suggested that the prevalence of biochemical hyperthyroidism in the study was 3%, with 13 of 415 cases in rural and 3 of 149 cases in urban subjects. CONCLUSION: This study reaffirms the need to continuously monitor iodine replacement programs to ensure efficacy.

Adult↗
PubMed1999

Iron overload in urban Africans in the 1990s.

BACKGROUND: In a previously described model, heterozygotes for an African iron loading locus develop iron overload only when dietary iron is high, but homozygotes may do so with normal dietary iron. If an iron loading gene is common, then homozygotes with iron overload will be found even in an urban population where traditional beer, the source of iron, is uncommon. AIMS: To determine whether iron overload and the C282Y mutation characteristic of hereditary haemochromatosis are readily identifiable in an urban African population. METHODS: Histological assessment, hepatocellular iron grading, and dry weight non-haem iron concentration were determined in post mortem tissue from liver, spleen, heart, lungs, and skin. DNA of subjects with elevated hepatic iron indexes was analysed for the C282Y mutation. Iron concentrations in other tissues were compared. RESULTS: A moderate increase (>30 micromol/g) in hepatic iron concentrations was found in 31 subjects (23%; 95% confidence interval 15.9 to 30.1%), and they were considerably elevated (>180 micromol/g) in seven subjects (5.2%; 95% confidence interval 1.5 to 8.9%). Appreciably elevated hepatic iron concentrations were associated with heavy iron deposition in both hepatocytes and macrophages, and either portal fibrosis or cirrhosis. All were negative for the C282Y mutation. Very high concentrations were uncommon in subjects dying in hospital. Concentrations of iron in spleen, heart, lung, and skin were significantly higher in subjects with elevated hepatic iron. CONCLUSIONS: Iron overload is readily identified among urban Africans and is associated with hepatic damage and iron loading of several tissues. The condition is unrelated to the genetic mutation found in hereditary haemochromatosis.

Adult↗
PubMed1999

Iron and alcohol content of traditional beers in rural Zimbabwe.

OBJECTIVES: To determine the concentrations of iron and alcohol in traditional beer, as well as how these may be related to the brewing process. DESIGN: Cross sectional study. SETTING/SUBJECTS: Rural communities living in four of Zimbabwe's nine provinces. MAIN OUTCOME MEASURES: Ionic iron concentration and alcohol concentration in 94 different types of alcoholic beverages prepared in rural areas, and 18 commercially produced beers. RESULTS: The commonest types of traditional beer were a seven day beverage called 'doro rematanda', a by-product of this seven day beer called 'muchaiwa,' and a one-day beverage called 'chikokiyana'. Methods of preparation were similar in the four provinces. Median (Q1, Q3) ionic iron concentrations were 52 (31 to 75) mg/L for the seven-day beer (n = 51), 24 (18 to 36) mg/L for muchaiwa (n = 30) and 21 (17 to 63) mg/L for chikokiyana (n = 13). In contrast, ionic iron concentrations in 12 samples of commercially prepared clear beers were 0.1 mg/L and in commercial opaque beer were 3.6 mg/L. Mean (SD) alcohol concentration in traditional beer was 4.1 g/100 ml (+/- 0.873) compared to 2.8 g/100 ml +/- 1.394) in the muchaiwa and 3.6 g/100 ml (+/- 1.445) in the one day brew, chikokiyana. Mean alcohol concentrations in the three commercial beers are reportedly 3.5 g/100 ml in the opaque beer (Scud), and 4.7 to 5.0 g/ml in clear beer (Zambezi and Castle lagers). CONCLUSIONS: Several preparation methods lead to traditional fermented beverages with very high iron concentrations. Measures to prevent dietary iron overload should include all of these beverages in their scope.

Beer↗
PubMed1998

Evidence of genetic transmission in African iron overload.

Iron overload in Africa was previously regarded as purely due to excessive iron in traditional beer, but we recently found evidence that transferrin saturation and unsaturated iron binding capacity may be influenced by an interaction between dietary iron content and a gene distinct from any HLA-linked locus. To determine if serum ferritin follows a genetic pattern and to confirm our previous observations, we studied an additional 351 Zimbabweans and South Africans from 45 families ranging in size from two to 54 members. Iron status was characterized with repeated morning measurements of serum ferritin, transferrin saturation, and unsaturated iron binding capacity after supplementation with vitamin C. For each measure of iron status, segregation analysis was consistent with an interaction between a postulated iron-loading gene and dietary iron content (P < .01). In the most likely model, transferrin saturation is 75% and serum ferritin is 985 micrograms/L in a 40-year-old male heterozygote with an estimated beer consumption of 10,000 L, whereas the saturation is 36% and serum ferritin is 233 micrograms/L in an unaffected individual with identical age, sex, and beer consumption. This segregation analysis provides further evidence for a genetic influence on iron overload in Africans.

Adult↗
PubMed1998

Pleural tuberculosis in Harare, Zimbabwe: the relationship between human immunodeficiency virus, CD4 lymphocyte count, granuloma formation and disseminated disease.

OBJECTIVE: To elucidate the relationship between HIV, CD4+ count and pleural TB. METHOD: In a prospective study, 94 patients presenting at two large Harare hospitals with clinically suspected pleural TB were enrolled over a 10-month period. All underwent standardized evaluation, closed pleural aspiration and biopsy. Patients receiving directly observed anti-TB therapy were followed-up. RESULTS: Pleural TB was diagnosed in 90 individuals (median age 33 years; range 18-65; 64 males); the seroprevalence of HIV was 85%. HIV-positive patients were older than HIV-negative individuals (median age 33 vs 23 years, P = 0.013) and had a significantly lower median CD4+ count (191 vs 1106 x 10(6)/l respectively, P = 0.004). A CD4+ count of <200 x 10(6)/l was associated with a length of illness >30 days (65% vs 37%; P = 0.05), a positive pleural fluid smear (37% vs 0%; P = 0.0006) and a positive pleural biopsy Ziehl-Neelsen stain (35% vs 7%; P = 0.021). However, a relationship between CD4+ count and either pleural granuloma formation or radiological evidence of disseminated disease was not observed. CONCLUSION: In sub-Saharan Africa, TB pleural effusions have become associated with older age, a chronic onset, and an increased mycobacterial load. These data emphasize the complex relationship between pleural TB, HIV infection and a low CD4+ count.

Adult↗
PubMed1998

Serum transferrin receptors are decreased in the presence of iron overload.

To test the hypothesis that the quantities of circulating transferrin receptors are reduced in iron overload, we studied serum transferrin receptors and indirect measures of iron status in 150 subjects from rural Zimbabwe. We found significant inverse correlations between serum concentrations of transferrin receptors and ferritin, the ratio of ferritin to aspartate aminotransferase, and transferrin saturation (r > or = 0.44; P < 0.001). The mean +/- SD concentration of serum transferrin receptors in 23 subjects classified as having iron overload (ferritin > 300 microg/L and transferrin saturation > 60%) was 1.55 +/- 0.61 mg/L, significantly lower than the 2.50 +/- 0.62 mg/L in 75 subjects with normal iron stores (ferritin 20-300 microg/L and transferrin saturation 15-55%; P < 0.0005) and the 2.83 +/- 1.14 mg/L in 8 subjects with iron deficiency (ferritin < 20 microg/L; P = 0.001). In keeping with the regulation of transferrin receptor expression at the cellular level, our findings suggest that serum transferrin receptors are decreased in the presence of iron overload.

Adolescent↗
PubMed1997

Traditional beer consumption and the iron status of spouse pairs from a rural community in Zimbabwe.

To examine the relationship between dietary iron exposure through the consumption of traditional beer and the presence of iron overload in black Africans not related by birth, we studied 28 husband and wife pairs from a rural Zimbabwean community. Lifetime traditional beer consumption was estimated by questioning subjects and iron status was assessed by repeated measurements of serum ferritin and transferrin saturation in subjects who were fasting and had received vitamin C supplementation. Each of the 56 study subjects had an estimated lifetime traditional beer consumption >1,000 L. The mean +/- standard deviation (SD) concentration of iron in the supernatants of nine samples of traditional beer from the community was 46 +/- 10 mg/L. Four of 28 men (14.3%) and no women had the combination of an elevated serum ferritin and a transferrin saturation >70%, suggestive of substantial iron overload. Significant correlations were not found between the iron status of the husbands and their wives or between dietary iron exposure and iron stores. Our findings suggest that dietary iron exposure may not fully explain the development of iron overload in Africans and are consistent with the hypothesis that an iron-loading gene may also be implicated in pathogenesis.

Aged↗
PubMed1997

Morbidity and disability in elderly Zimbabweans.

BACKGROUND: the population aged over 60 years in Zimbabwe is expanding. Despite the likely increased demand on medical services that this will bring, little is known about the health needs of this elderly population. OBJECTIVE: to record the prevalence of disability (impairment of activities of daily living), subjective morbidity (symptoms), the social circumstances and the utilization of health services in a group of elderly Zimbabweans. DESIGN: cross-sectional community survey. SETTING: a remote rural area in North Eastern Zimbabwe and two urban townships located approximately 80 km from Harare. SUBJECTS: 278 subjects (154 women, 174 rural), aged > 60 years (range 60-92) living at home. METHOD: subjects were selected by random cluster sampling. They were assessed in a structured interview and underwent physical examination including visual acuity, inspection for cataracts and assessment of mobility. RESULTS: less than 4% experienced difficulty with self-maintenance activities of daily living, but 30% had difficulty with instrumental activities. The former were all visually impaired and both visual and mobility problems contributed to the latter. Elderly people experienced many symptoms but had inadequate access to health services and used medication infrequently. Subjects were mainly self-sufficient for financial income and 60% still worked. They had declining resources with age and received little help from the social welfare department. Their health and functional abilities deteriorated with age but it was older subjects who had most difficulty getting to the clinic. Simple measures such as cataract surgery and analgesics were available only to the minority or not at all. CONCLUSIONS: this study highlights problem areas where simple, low-cost measures could make a difference to the morbidity and disability of elderly Zimbabweans.

Activities of Daily Living↗
PubMed1997

Diet and nutritional status in elderly Zimbabweans.

BACKGROUND: nutritional studies in developing countries tend to focus on women of reproductive age and children. Little is known about the diet or nutritional status of elderly Africans. OBJECTIVE: to record the diet, anthropometric, haematological and biochemical measurements which might reflect nutrition and social factors in a group of elderly Zimbabweans. DESIGN: cross-sectional community survey. SETTING: a remote rural area in north-eastern Zimbabwe and two urban townships located approximately 80 km from Harare. SUBJECTS: 278 subjects (154 women, 174 rural), aged >60 years (range 60-92), living at home. METHOD: subjects were selected by random cluster sampling. Diet was assessed by a food frequency questionnaire. Anthropometric measurements were body mass index (BMI), waist : hip ratio (WHR), triceps and subscapular skinfold thickness (SFT). Laboratory analysis included serum albumin, calcium, haemoglobin, alkaline phosphatase (ALP), cholesterol, triglycerides, vitamin B12 and red blood cell folate levels. RESULTS: the staple diet was maize meal and vegetables; 74 (27%) ate a protein-containing meal less than once a week; 135 (49%) took milk less than once a week and 27% had serum Ca2+ < 2 mmol/l. The frequency of eating meat, milk, bread and fried food varied with income and education and declined with age. For all anthropometric measurements median values were higher in the urban area (BMI 21.1 vs 18.3, WHR 0.98 vs 0.9, triceps SFT 10 vs 6.7 mm; P < 0.001 for all) and related to the frequency of eating meat and fried food. The BMI was higher in those with more years of education. Within the rural area physical measurements were higher in a more prosperous area. Serum lipid concentrations were higher in urban residents (median cholesterol 4.4 vs 3.9 mmol/l, triglycerides 1.8 vs 1.5 mmol/l; P < 0.001 for both) and correlated with BMI, WHR and triceps SFT. Vitamin B12 concentrations were higher in urban residents, whereas folate concentrations were higher in rural residents. CONCLUSIONS: dietary patterns, anthropometric measurements and biochemical values in a group of randomly-selected elderly Zimbabweans are influenced by area of residence, age, income and educational level.

Aged↗
PubMed1996

Abbreviated Mental Test (AMT) in the elderly: shortcoming of an adapted AMT in Zimbabwe.

OBJECTIVE: To measure the abbreviated mental test (AMT)-and to determine factors which might influence this in a group of Zimbabwean elders. DESIGN: Community based cross sectional survey. SETTING: Randomly selected households within randomly selected villages and two high-density urban areas in north eastern Zimbabwe. SUBJECTS: 278 subjects aged 60 to 92 years (124 male, 154 female). INTERVENTIONS: A questionnaire, including the AMT, was administered, at home, by trained research nurses. MAIN OUTCOME MEASURES: AMT-literacy rates, visual acuity, social and demographic information. RESULTS: 128 (46pc) scored less than seven, a level normally associated with significant mental impairment. Only one subject was actually disoriented in time and place. Multiple regression analysis confirmed that increasing age, female sex, rural evidence, lack of formal education, reduced visual acquity and not currently living with a spouse were all independent factors associated with low AMT score. CONCLUSION: It was apparent that the AMT was not a valid tool for screening for confusion in Zimbabwean elderly, since the prevalence of senile-dementia is increasing in the developing world. It is important to develop a screening test for use in Zimbabwe which is sensitive but is independent of these confounding variables.

Aged↗