One hundred and thirty-two newly diagnosed Asian diabetic patients (39 Malay, 30 Chinese and 63 Indians) have been studied in Kuala Lumpur. The highest proportion of diabetic patients were Indian and the lowest were Chinese. Vascular complications were equally common in Asian diabetic patients as in Europeans; coronary heart disease was relatively more common in Indians and cerebral vascular disease in Chinese. Twenty percent of all Asian diabetic patients requiring admission to hospital also had coronary heart disease, 9% had cerebral vascular disease and 8% had gangrene or ulceration of the feet. In Kuala Lumpur, diabetes is a very important risk factor for coronary heart disease: 17% of all patients admitted to the General Hospital with coronary heart disease were already diabetic.
Coronary atheroma is the principal cause of ischaemic heart disease. Among the factors considered to predispose to atheroma formation is raised plasma cholesterol and although it is regarded as a minor risk factor by some, others see its contribution as one of major importance. Whichever the view, the debate on plasma cholesterol and coronary heart disease (CHD) has long moved out of the exclusive domain of the scientific journal to the public arena and is reflected in the increasing frequency with which doctors are consulted by patients on the subject. The incidence of CHD in South-East Asian countries is also rising. For the practising clinician, the problem resolves itself into deciding if the evidence incriminating plasma cholesterol as a predisposing factor is strong enough, and if it is, what prophylactic and therapeutic steps are of value in reducing the incidence of CH D. An updated and brief review of lipid metabolism and the relationship of lipids to CHD is now necessary in view of the rapid accumulation of data from recent trials and prospective studies.
The mortality from coronary artery disease (CAD) in Indians is more than three times that in the Chinese and Malays of Singapore. Serum total and HDL cholesterol as well as apolipoprotein (Apo) AI, AII and B levels were determined in a group of 349 newborns (cord blood) from both sexes in these three ethnic groups in order to examine if a trend is reflected at birth. Both serum LDL cholesterol and Apo B levels were low in the newborn, while HDL cholesterol and Apo AII levels were almost the same as in adults. Serum Apo AI levels were also low in newborns. No consistent difference as to ethnic group or sex was observed in any of the parameters investigated, except that the females had significantly higher levels of serum Apo AI in all the ethnic groups. Serum total and HDL cholesterol levels in Singapore newborns were comparable to those reported in Caucasians and Asians. The trends of incidence of CAD were not reflected in the lipid profiles studied at birth.
Coronary heart disease which was responsible for 2.9% of all deaths 30 years ago, today accounts for 19% of deaths. The rising trend which declined in 1985, appears to be stabilising now. Indians have mortality rates which are 3 times that of Chinese. This is the background against which the Singapore Myocardial Infarction Register was set up in 1967 to provide incidence and prevalence data for coronary heart disease in the country. in 1987 to provide incidence and prevalence data for coronary heart disease in the country.
Key words: Coronary heart disease mortality, Age standardised death rates, Ethnic differences, Singapore Myocardial Infarction Register
Mortality from ischaemic heart disease in Singapore is now reaching comparability with the West. For the early 1980s, rates for Indians and Malays were higher than in U.S.A. and England and Wales and while those for Chinese were lower they were considerably higher than in Japan. In keeping with this the levels of the major risk factors in Singapore are now comparable to the West. Cigarette smoking in males is virtually the same as in Britain, while the proportion of hypertensives on medication is higher than in the West. The main cause for concern is the current high levels of serum cholesterol in Singapore and strenuous health education efforts are needed to bring about dietary changes.
The effect of a capsulated palm-oil-vitamin E concentrate (palmvitee) on human serum and lipoprotein lipids was assessed. Each palmvitee capsule contains approximately 18, approximately 42, and approximately 240 mg of tocopherols, tocotrienols, and palm olein, respectively. All volunteers took one palmvitee capsule per day for 30 consecutive days. Overnight fasting blood was taken from each volunteer before and after the experiment. Serum lipids and lipoproteins were analyzed by using the enzymatic CHOD-PAP method. Our results showed that palmvitee lowered both serum total cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C) concentrations in all the volunteers. The magnitude of reduction of serum TC ranged from 5.0% to 35.9% whereas the reduction of LDL-C values ranged from 0.9% to 37.0% when compared with their respective starting values. The effect of palmvitee on triglycerides (TGs) and HDL-C was not consistent. Our results show that the palmvitee has a hypocholesterolemic effect.
The effects on serum lipids of diets prepared with palm olein, corn oil, and coconut oil supplying approximately 75% of the fat calories were compared in three matched groups of healthy volunteers (61 males, 22 females, aged 20-34 y). Group I received a coconut-palm-coconut dietary sequence; group II, coconut-corn-coconut; and group III, coconut oil during all three 5-wk dietary periods. Compared with entry-level values, coconut oil raised the serum total cholesterol concentration greater than 10% in all three groups. Subsequent feeding of palm olein or corn oil significantly reduced the total cholesterol (-19%, -36%), the LDL cholesterol (-20%, -42%%) and the HDL cholesterol (-20%, -26%) concentrations, respectively. Whereas the entry level of the ratio of LDL to HDL was not appreciably altered by coconut oil, this ratio was decreased 8% by palm olein and 25% by corn oil. Serum triglycerides were unaffected during the palm-olein period but were significantly reduced during the corn-oil period.
We studied the effects of saturated (palm olein) and polyunsaturated (soybean oil) cooking oils on the lipid profiles of Malaysian male adolescents eating normal Malaysian diets for 5 wk. Diets cooked with palm olein did not significantly alter plasma total-cholesterol, LDL cholesterol, and HDL cholesterol concentrations or the ratio of total cholesterol to HDL cholesterol compared with diets cooked with soybean oil. However, the diet cooked with palm olein significantly increased apolipoprotein A-I (11%) and apolipoprotein B (9%) concentrations. Unexpectedly, soybean-oil-cooked diets caused a significant increase (47%) in plasma triglycerides compared with palm-olein-cooked diets. We conclude that palm olein, when used as cooking oil, has no detrimental effects on plasma lipid profiles in Malaysian adolescents.
To compare the effects of dietary palmitic acid (16:0) vs oleic acid (18:1) on serum lipids, lipoproteins, and plasma eicosanoids, 33 normocholesterolemic subjects (20 males, 13 females; ages 22-41 years) were challenged with a coconut oil-rich diet for 4 weeks. Subsequently they were assigned to either a palm olein-rich or olive oil-rich diet followed by a dietary crossover during two consecutive 6-week periods. Each test oil served as the sole cooking oil and contributed 23% of dietary energy or two-thirds of the total daily fat intake. Dietary myristic acid (14:0) and lauric acid (12:0) from coconut oil significantly raised all the serum lipid and lipoprotein parameters measured. Subsequent one-to-one exchange of 7% energy between 16:0 (palm olein diet) and 18:1 (olive oil diet) resulted in identical serum total cholesterol (192, 193 mg/dl), low-density lipoprotein cholesterol (LDL-C) (130, 131 mg/dl), high-density lipoprotein cholesterol (HDL-C) (41, 42 mg/dl), and triglyceride (TG) (108, 106 mg/dl) concentrations. Effects attributed to gender included higher HDL in females and higher TG in males associated with the tendency for higher LDL and LDL/HDL ratios in men. However, both sexes were equally responsive to changes in dietary fat saturation. The results indicate that in healthy, normocholesterolemic humans, dietary 16:0 can be exchanged for 18:1 within the range of these fatty acids normally present in typical diets without affecting the serum lipoprotein cholesterol concentration or distribution. In addition, replacement of 12:0 + 14:0 by 16:0 + 18:1, but especially 16:0 or some component of palm olein, appeared to have a beneficial impact on an important index of thrombogenesis, i.e., the thromboxane/prostacyclin ratio in plasma.