The incidence of surgery for gastric cancer in Singapore increased during the period 1951 to 1980 (males from 3.5 to 8.7 per 100,000 per year: females from 0.5 to 4.2 per 100,000 per year). This increase occurred mainly during the first decade of the study and was confined to persons aged 55 and above. Chinese had the highest incidence, followed by Indians and then Malays. These racial differences remained unchanged over the period of study.
The influence of the age of onset of symptoms on various clinical features of peptic ulcer was studied in a personal series of 492 patients (duodenal ulcer 363, gastric ulcer 98, combined gastric and duodenal ulcer 31). Duodenal ulcer patients whose age of onset of symptoms was within the first three decades (n = 166) were more likely to be men (77%) and to have a positive family history of dyspepsia (45%) and a history of haemorrhage (46%) when compared with late onset patients (n = 197, men 57%, positive family history 23%, history of haemorrhage 36%). Early onset duodenal ulcer patients also secreted more gastric acid than late onset patients. In contrast, while early onset gastric ulcer patients were more likely to be men, when compared to late onset patients, the two groups were similar in their family history of dyspepsia, their history of haemorrhage, and their gastric acid output. The age of onset of Malay duodenal ulcer patients (mean (SD) 43.6 (16.0] was higher than those for Chinese patients (33.7 (16.1].
Several lines of evidence suggest that, of the three main races of Singapore, peptic ulcers are more common among the Chinese and Indians when compared to the Malays. These include studies on hospital series of patients with or without appropriate control groups, studies on the incidence of surgery for perforated ulcer as well as mortality statistics. A reduction in the Chinese:Malay difference in the incidence of perforated ulcer over three decades suggests that environmental factors are involved in producing these racial differences. However, we have to date been unable to determine the factor(s) responsible. The incidence of perforated ulcer in Singapore is increasing while ulcer mortality is declining. This is similar to the situation in Hong Kong but different from that in the western countries.
A consecutive series of 2,277 patients presenting for upper gastrointestinal endoscopy was analysed. The following groups of patients were studied with reference to sex, race and dialect groups: those presenting with dyspepsia but no haemorrhage, those presenting with upper gastrointestinal haemorrhage, those with non-ulcer dyspepsia, gastric ulcer and duodenal ulcer. Males out-numbered females in all diagnostic groups. Male and female Malays were under-represented in all diagnostic groups when compared to the Singapore population. Amongst female Chinese, there was an excess of Cantonese patients and an under-representation of Teochew patients in most diagnostic groups. These dialect differences were not remarkable amongst male Chinese. The possible reasons for these differences and their significance are discussed.
We report the first double-blind, placebo-controlled study that assesses the efficacy and safety of omeprazole 20 mg daily in the maintenance treatment of duodenal ulcer. For the healing phase, 128 patients with endoscopically proven active duodenal ulcer and a history of three or more relapses during the 2 years prior to the study were treated until healing with omeprazole 40 mg daily for 2 and up to 8 weeks. One hundred and twenty-three patients whose ulcers were healed were randomized to receive omeprazole 20 mg daily (n = 60) or placebo (n = 63) for 12 months as maintenance treatment. Patients were interviewed at 3, 6, 9 and 12 months, and endoscopy was performed at 3, 6 and 12 months and whenever symptoms recurred. The healing rates of the 124 patients completing the healing phase were 84, 98 and 100% at 2, 4 and 8 weeks, respectively. During the maintenance phase, eight and four patients discontinued treatment from the omeprazole and placebo groups, respectively. The proportion of patients in remission in the omeprazole group and placebo group after 12 months were 94 and 9% respectively (life table estimates, P < 0.0001). No significant clinical or laboratory changes were observed in patients on therapy with omeprazole. Patients with a history of frequent relapses thus continued to have a very high relapse rate without prophylactic treatment. Omeprazole 20 mg daily was effective and safe in maintaining such patients in remission.
Thirty-one patients with endoscopically proven chronic gastric ulcer completed a randomised double-blind trial comparing the effects of cimetidine and placebo on ulcer healing. Seventeen patients received cimetidine 400 mg bid and 14 patients received placebo. Repeat endoscopy at six weeks showed that the ulcer had healed in 12 patients (71%) receiving cimetidine and in four patients (29%) receiving placebo (p=O.032). Non-smokers healed their ulcers better than smokers (83% vs 35%, p=O.023). The use of cimetidine was not associated with any adverse effects.
Peptic ulcer occurs with different frequencies in the three main racial groups in Singapore. This study aimed firstly to determine the prevalence of Helicobacter pylori in peptic ulcer and non-ulcer dyspepsia patients of the different races and secondly, to assess the relation between H pylori, histological gastritis, patient diagnosis, and race. Gastric antral biopsy specimens from 1502 patients undergoing gastroduodenoscopy were studied and 892 (59%) were positive for H pylori. H pylori was strongly associated with gastritis: 873 of 1197 (73%) patients with gastritis were positive compared with 19 of 305 (6%) without gastritis (p less than 0.0001). The prevalences of H pylori and gastritis were similar in peptic ulcer patients of different races. Malay patients with non-ulcer dyspepsia, however, were less likely to be positive for H pylori (10 of 46 (22%] or to have antral gastritis (17 of 46 (37%] than Chinese (292 of 605 (48%) were positive for H pylori and 421 of 605 (70%) had gastritis) and Indians (35 of 61 (57%) were H pylori positive and 42 of 61 (69%) had gastritis). Patients with duodenal ulcer were more likely to be positive for H pylori than those with non-ulcer dyspepsia, even when subjects with gastritis were considered separately. While our results do not help to explain the observed racial differences in peptic ulcer frequency it may be that the pathophysiology of non-ulcer dyspepsia is different in the different races in Singapore.
The aim of this study was to determine, first, whether racial differences exist in the seroprevalence of Helicobacter pylori infection in Singapore, and second, whether these differences correlate with racial differences in peptic ulcer frequency. A commercial serological test for immunoglobulin (Ig)G antibody to H. pylori which was 90% sensitive and 83% specific in our population was used to screen 403 adult blood donors of Chinese, Malay and Indian origin, aged between 15-60 years. Serum specimens from 84 paediatric patients admitted to the Paediatrics Department, National University of Singapore, with non-gastroenterological illnesses were also tested. In all three races, seroprevalence of H. pylori increased with age. Indians have the highest prevalence of infection followed by Chinese and Malays. Peptic ulcer prevalences are known to be highest in Chinese, followed by Indians and Malays. The Malays have the lowest prevalence of H. pylori and peptic ulcer among the three races in Singapore. Indians have a higher prevalence of H. pylori antibodies but a lower frequency of peptic ulcer than the Chinese. Racial differences in peptic ulcer frequency between Chinese and Indians are not explained by the prevalence of H. pylori infection; other environmental or genetic factors may be involved.