Twenty-four-hour oesophageal pH studies in rural Eastern Cape Province, South Africa.

BACKGROUND: Recent studies in rural Eastern Cape Province, South Africa, have shown an increased number of non-acid gastro-oesophageal reflux events, an increase in baseline gastric pH compared with other published series, and evidence suggestive of duodenogastric reflux. There are no published data on oesophageal pH in this community or in Africa. OBJECTIVES: To ascertain whether oesophageal pH in this rural community is within normal limits. METHODS: We carried out 24-hour oesophageal pH/impedance studies on 91 participants. Analysis was carried out using computer software to determine 24-hour percentage times of oesophageal pH above 4, 5, 6, 7 and 8. Oesophageal pH during each episode of non-acid reflux was also recorded. RESULTS: Participants were from Canzibe in rural Eastern Cape. Of the studies, 72 were satisfactory and showed 24-hour percentage times with an oesophageal pH >6 of 69.3/35.12/51.16 (upright/supine/total); percentage times with a pH >7 were 12.66/3.44/8.86 and those with a pH >8 were 0.48/0.21/0.37. These results are within the range of other published series. Of episodes of non-acid reflux, 90.2% were associated with an oesophageal pH of 4 - 7. CONCLUSIONS: Baseline oesophageal pH is not significantly affected by the increased numbers of non-acid gastro-oesophageal reflux events reported in this community. If there is a pathogenic effect of non-acid reflux in the Eastern Cape, it does not appear to be mediated through raised oesophageal pH.

Diet affects reflux in a rural African community.

Reflux in this region of South Africa is known to be more frequent and less acidic than in other countries. We investigated the relationship between reflux and diet. We recruited 57 healthy participants. We carried out ambulant oesophageal pH-impedance monitoring for 24 hours. We used software and visual review to analyse data and to identify episodes of reflux and rapid alkaline rises in the stomach. A usual pattern diet questionnaire provided data on frequency of consumption of common foods. Associations between reflux, gastric pH and dietary components were sought using analysis of variance, and regression analyses. Diet was strongly based on maize. Protein was principally from milk, eggs, chicken and beans. Fat was principally from cooking oil. Fruit and vegetables were consumed moderately frequently. Milk consumption was associated with an increase in total reflux (P = .022), weakly acid reflux (P = 0.015) and supine reflux (P = 0.001), and a decrease in the time that gastric pH was higher than 4 (P = 0.030). Fat was associated with an increase in acid reflux (P = 0.046) and a decrease in time that gastric pH was higher than 4 (P = 0.005). Fruit consumption was associated with increases in liquid-only refluxes(P = 0.007), and upright refluxes (P = 0.048). Maize meal was associated with a reduction in rapid alkaline rises in the gastric lumen (P = 0.015). Diet significantly affects reflux in this community. What is normal in apparently healthy people in various parts of the world differs significantly.

Normal values of 24-hour ambulatory esophageal impedance-pH monitoring in a rural South African cohort of healthy participants.

There are no data on 24-hour multichannel intraluminal impedance and pH monitoring in African populations. The purpose of this study was to provide the normal values of esophageal impedance and pH monitoring in a rural African populations. South African healthy rural participants were recruited and underwent 24 hours of esophageal impedance and pH monitoring. The median and the 95th percentiles of the total reflux episodes were 49 and 97, respectively, of which the corresponding number of acidic, weakly acidic, and weakly alkaline reflux were 15 and 55, 17 and 51, and 8 and 36, respectively. The compositions of the total reflux were 5 and 21 for liquid, 27 and 72 for mixed, and 10 and 39 for gas reflux, respectively. The median bolus clearance was 18 seconds and the median bolus exposure was 14 minutes/24 hours. The proximal extent was 6%. The 95th percent time of esophageal exposure to acid was 8.6 in 24 hours. Female and overweight participants were associated with an increased number of reflux events. There were more reflux episodes, and of which, more were weakly alkaline compared with previous similar studies. The findings provide reference values of gastroesophageal reflux for a South African rural population.

Maize meal predisposes to endemic squamous cancer of the oesophagus in Africa: breakdown of esterified linoleic acid to the free form in stored meal leads to increased intragastric PGE2 production and a low-acid reflux.

Endemic cancer of the oesophagus in Africa is associated with the use of maize as the staple. In one African community endemic cancer of the oesophagus has been shown to have a strong statistical association with the consumption of foods based on maize in the meal form. A strong association with consumption of maize meal has also been shown in a region of Italy. It has been argued in the past that the association with maize consumption is due to a fortuitous association; or due to the nutritional deficiencies of maize meal; or due to fungal contamination. We argue that maize meal is a distinctly different food from whole maize, and that nutritional content as much as deficiency is responsible for predisposition of the oesophagus to carcinogenesis. An important factor is the breakdown of esterified linoleic acid to the free form in stored maize meal. This leads to excess production of prostaglandin E2 in the stomach. The excess Prostaglandin E2 causes a low-acid duodenogastro-oesophageal reflux, which predisposes to carcinogenesis. Supporting evidence is available that the steps of this mechanism occur in endemic areas, and that they are associated with the carcinogenic process. Health measures including poverty alleviation, health education, and monitoring and control of maize meal storage and content may be required to reduce the incidence of this disease in Africa.

Gastric luminal epidermal growth factor is affected by diet.

OBJECTIVE: Diet is an area of major interest to those investigating the causes of cancer of the oesophagus in the Transkei. This study looked at the associations between intragastric epidermal growth factor level, diet and intragastric pH. SETTING AND SUBJECTS: A dietary survey was co-ordinated with studies of gastric luminal epidermal growth factor and gastric fluid pH in 120 rural Transkeians. RESULTS: Gastric fluid epidermal growth factor was associated with low dietary intake of animal products (p = 0.002) and vegetables (p = 0.026). There was no association with pH. CONCLUSION: A dietary subgroup has been identified in the Transkei population with high levels of epidermal growth factor in the upper gastrointestinal lumen. This adds to previously demonstrated diet-related changes in the upper gastrointestinal tract in Transkei. These changes may affect the disease pattern of the population.

Bimodal distribution of fasting gastric acidity in a rural African population.

SETTING: The people of Transkei eat a diet high in linoleic acid, the principal fatty acid in maize. The theory has been put forward that a diet high in linoleic acid and low in fat and riboflavin, such as the traditional diet in Transkei, results in overproduction of prostaglandin E2 in the gastric mucosa, and that this overproduction in turn causes a suppression of gastric acid production. OBJECTIVE: To investigate the effect of diet on fasting gastric pH in a rural black African population. DESIGN: Fasting gastric acid samples were obtained by fine nasogastric tube aspiration from 150 volunteers at a rural health clinic. The pH of these samples was measured and a full dietary questionnaire was used. Helicobacter pylori serology was done on a subgroup of 30 volunteers. RESULTS AND CONCLUSIONS: A bimodal pH distribution was found. Approximately half the population had a gastric pH within the range 1-4. Half had a pH of over 4. A high pH was significantly associated with consumption of maize (p = 0.006), and with consumption of both pumpkin and beans (p = 0.006). A high proportion of this rural African population has a diet-associated abnormally high gastric pH. The pattern of upper gastrointestinal disease may be significantly affected by diet in this community and in others with a similar diet.

Prostaglandin E2 is raised in kwashiorkor.

OBJECTIVE: Infection is a common occurrence in children with kwashiorkor. It has been suggested that infection in kwashiorkor results from immune depression, and that the immune depression of kwashiorkor is caused by a diet-associated elevation of prostaglandin E2 (PGE2). The purpose of this study was to determine whether levels of PGE2 are abnormal in children with kwashiorkor. SETTING AND SUBJECTS: Plasma PGE2 and plasma proteins were measured in children admitted with oedematous kwashiorkor, and compared with PGE2 in children with cerebral palsy. RESULTS: Plasma PGE2 was higher in children with kwashiorkor than in control children (7.25 +/- 3.5 v. 3.51 +/- 1.59, P < 0.01). Within the kwashiorkor study group there was a significant negative correlation between log-transformed serum PGE2 and total plasma protein (r = -0.59, P < 0.001), plasma albumin (r = -0.63, P < 0.001), weight-for-age (r = -0.37, P < 0.05), and height-for-age (r = -0.37, P < 0.05). The difference in mean values of PGE2 in children with kwashiorkor who recovered from the illness and those who died was not significant (7.1 +/- 2.6 v. 9.1 +/- 4.8, P = 0.36). CONCLUSION: Significantly higher PGE2 levels in children with kwashiorkor provide adequate reason for the depression of immune function known to occur in these children. Elevated PGE2 levels may also be implicated in other components of the illness.

A prepaid healthcare scheme in rural Africa.

Healthcare providers in Africa are having to increasingly rely on the resources of the populations they serve. An 8-year experience with one of the first rural-based health insurance schemes in East Africa is described. Initial difficulties included adverse selection of members with chronic ill health, fraudulent claims and overuse of health services, leading to considerable financial losses. External technical assistance introduced member tracking and regular reports, reduced adverse selection, fraud and overuse of services to a minimum, and achieved financial stability. Local market research and a comprehensive marketing plan is essential for the overall success of an insurance plan. Health insurance in this part of Africa is likely to assist middle income earners rather than the poor.

Dietary linoleic acid, immune inhibition and disease.

Review of the evidence available in published literature supports a radical change in viewpoint with respect to disease in countries where maize is the predominant dietary component. In these countries, the pattern of disease is largely determined by a change in immune profile caused by metabolites of dietary linoleic acid. High intake of linoleic acid in a diet deficient in other polyunsaturated fatty acids and in riboflavin results in high tissue production of prostaglandin E2, which in turn causes inhibition of the proliferation and cytokine production of Th1 cells, mediators of cellular immunity. Tuberculosis, measles, hepatoma, secondary infection in HIV and kwashiorkor are all favoured by this reduction in cellular immunity. Diet-associated inhibition of the Th1 subset is a major contributor to the high prevalence of these diseases found in areas of sub-Saharan Africa where maize is the staple.

Maize meal, non-esterified linoleic acid, and endemic cancer of the esophagus--preliminary findings.

Endemic cancer of the esophagus has shown a positive association with the consumption of maize meal. It has been postulated that this association is due to the conversion, in the stomach mucosa, of the linoleic acid contained in maize meal to prostaglandin E2. The proportion of non-esterified linoleic acid available in the stomach may therefore be an important factor. Samples of commercially prepared maize flour, cooked and uncooked, and other maize-based foods were analysed for total and free content of various fatty acids using gas-liquid chromatography. High levels of non-esterified fatty acids (11 to 42% of contained fatty acids) were found both in maize meal and in foods prepared from it. In food prepared from maize meal, 49 mg to 363 mg non-esterified linoleic acid per 100-g sample was found. High levels of non-esterified linoleic acid in the diet, causing raised intragastric production of prostaglandin E2 and profoundly affecting the normal pH and fluid content of the esophagus, may create a predisposition to esophageal carcinogenesis.

Protease inhibitors and carcinoma of the esophagus.

BACKGROUND: Squamous cell carcinoma of the esophagus is endemic in parts of South Africa. Previous case-control studies have shown many associations but no clear etiologic pathway has been established. METHODS: A case-control study of dietary and social factors was performed for 130 patient/control pairs matched for age, gender, and educational level. Staple diet, consumption of wild vegetables, use of tobacco, and traditional beer consumption were compared between the two groups. RESULTS: New significant associations were found with the consumption of beans (P = 0.016) and consumption of the full traditional diet of maize, pumpkin, and beans (P = 0.027). Known associations with the consumption of Solanum nigrum (P = 0.018) and with smoking (P = 0.002) were confirmed by multiple regression analysis. CONCLUSIONS: Solanum nigrum, beans, and pumpkin all contain protease inhibitors. Suppression of protease inhibitors can lead to overexpression of growth factors in the esophagus, resulting in a proliferative and oncogenic drive.

Diet, reflux and the development of squamous cell carcinoma of the oesophagus in Africa.

BACKGROUND: Squamous cancer of the oesophagus has reached epidemic proportions in Africa in the past few decades. There are many known associations but as yet no well established theory of causation. METHODS: Relevant literature was found by manual review of appropriate journals and literature, Medline searches and cross-referencing. Published theories of causation of endemic cancer of the oesophagus were assessed in the light of available evidence. A hypothesis based on that evidence was formulated. RESULTS AND CONCLUSION: A predominantly maize-based diet is high in linoleic acid, a precursor for gastric prostaglandin synthesis. In combination with low intake of other fatty acids and riboflavin, high levels of prostaglandin E2 are produced in gastric mucosa, leading to reduced gastric acid secretion, relaxation of the pylorus and a reduction in lower oesophageal sphincter pressure. These events result in combined reflux of duodenal and gastric juices low in acidity into the oesophagus. Resulting dysplasia strongly predisposes to local squamous carcinogenesis. This is now a fertile area for research, which may open the way for preventive action.

An integrated approach to health care financing--the case of Chogoria Hospital.

A response to the increasing financial crisis for African hospitals is presented. The first measure is careful health care system design. Cost to the community can be reduced by cost-containment, income generation, and seeking of donations. Community ability to pay can be boosted by community financial development and community insurance. The final measure is continual appropriate level setting.

A case-control study of diet and social factors in cancer of the esophagus in Transkei.

A study of 100 patients with cancer of the esophagus and 100 controls matched for sex, age, and educational level was done in Transkei, with extensive inquiries into diet and social habits. The significant risk factors found were use of Solanum nigrum as a food (relative risk, 3.6), smoking (relative risk, 2.6), and use of traditional medicines (relative risk, 2.1). Consumption of traditional beer was not a risk factor.

Early detection of incorrect siting of Procter-Livingstone tube by fibre-optic endoscopy.

Forty patients undergoing intubation with a Procter-Livingstone tube for oesophageal neoplasm were checked by gastroscope for correctness of placement. An end-viewing fibre-optic scope was passed through the rigid oesophagoscope, through the Procter-Livingstone tube and onwards into whatever structure lay beyond. Oesophageal perforation occurred in 6 patients and immediate salvage operations resulted in 4 surviving. Reduced hospital mortality and educational feedback for the operator were the major advantages.

Carcinoma of the oesophagus in Transkei: treatment by intubation.

The management of carcinoma of the oesophagus poses formidable logistic problems in countries such as Transkei where the condition is common and resources are limited. Most patients present late, often with complications, and are reluctant to undergo major surgery. Two hundred and fifty consecutive patients who presented over nine months in Transkei were studied. The incidence increased with age until 70 years and the disease occurred equally in men and women. The neoplasm was predominantly squamous cell (243 patients, 97%) and was found most often in the middle third of the oesophagus (118, 47%). On admission only eight of the 250 patients could take a semi-solid diet and only 21 a fluid diet. The policy where feasible was to introduce a Proctor Livingstone tube endoscopically through the dilated oesophageal stricture by a pulsion technique under light general anaesthesia. When abdominal perforation of the oesophagus seemed likely, retrograde intubation via a gastrotomy was performed. Sixty patients were not intubated, because the stricture was too proximal (47) or could not be dilated adequately (6), the lesion was suitable for resection (6), or the patient refused (1). Fifty one (27%) patients died in hospital, 29 deaths being due to oesophageal perforation (including six of the 10 who were intubated retrogradely). The mean hospital stay was 4.7 days. On discharge 64% of the intubated patients were able to take semi-solid food and a further 6% a fluid diet. Palliation by intubation was performed rapidly and the tube was well tolerated by patients. The overall mortality was high, but this can be reduced by experience. Intubation is an acceptable, cost effective solution where large numbers of patients present with advanced oesophageal carcinoma in circumstances where resources are severely limited.

Body composition in cachexia resulting from malignant and non-malignant diseases.

The body composition of 23 patients with cachexia resulting from malignant or benign inflammatory disease was studied. Skinfold thickness and radioisotope tracer measurements enabled us to estimate total body fat, lean body mass, the ratio of fat loss to lean body loss, erythrocyte and plasma volumes, total body water, extra-, and intracellular water volumes, total body potassium, and intracellular potassium concentration. The total body fat and lean body mass information suggests that the body composition in cancerous cachexia differs from that in cachexia caused by benign inflammatory disease, in that lean tissue appears to be better conserved in the former. The radioactive tracer studies showed that the cachectic patients were anemic, potassium-deficient, and overhydrated; however, fluid partitioning into extra- and intracellular compartments was normal.