Despite recent progress in reducing mortality associated with coronary heart disease (CHD), it is still the number one cause of the death in the United States. The major risk factors for CHD are well known and have been studied extensively.1 One way of studying these risk factors is to follow large groups of individuals over a long period of time, keeping track of their health behaviors and other relevant indictors, and seeing who ultimately develops CHD and who does not.2It is well proved that fats in our body are the major risk factors for the development of CHD.3Cholesterol is responsible to synthesize many hormones, vitamin D, and the bile acids that help to digest fat. It takes only a small amount of cholesterol in the blood to meet these needs.4,10,12 If human body have too much cholesterol in bloodstream, the excess is deposited in arteries, including the coronary arteries, where it contributes to the narrowing and blockages that cause the signs and symptoms of heart disease.5Psyllium or Plantago ovata Forsk is an annual plant grown primarily in India, southern Europe and the United States. Psyllium is cultivated primarily for its use as a laxative or as a dietary fiber ingredient in foods, such as ready-to-eat cereals. It is also known as blond psyllium, Indian psyllium and plantain. Although the seed alone contains the bioactive mucilage polysaccharide, the refined psyllium seed husk, known as the Ispaghula husk, is the psyllium component principally used as the soluble fiber source for laxatives, ready-to-eat cereals and nutritional supplements.6,9 In specific doses, it lowers serum total cholesterol and LDL- Cholesterol remarkably.7 Psyllium husk fiber is a viscous, mostly water-soluble fiber prepared by mechanical removal of the husk from blonde psyllium seed (Plantago ovata). Early or uncontrolled studies suggested that psyllium improved glycemic and lipid control in individuals with type 2 diabetes.8,14
The mechanism of psyllium’s possible hypocholesterolemic activity is not fully understood. The bioactive agent of psyllium is a soluble, viscous xylan fiber. It is thought that this polysaccharide stimulates the conversion of cholesterol to bile acids and that it stimulates fecal excretion of bile acids. Psyllium may also decrease the intestinal absorption of cholesterol.9
PATIENTS&METHOD
Study was conducted in the department of Pharmacology, Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi, from January to July 2006.Forty patients of primary hyperlipidemia were enrolled in the study, selected from ward and OPD of National Institute of Cardiovascular Diseases (NICVD), Karachi. Previously diagnosed and untreated primary hyperlipidemic patients of either sex, age range from 21 to 60 years were randomly selected. Patients with peptic ulcer, hepatic disease, alcoholism, hypothyroidism, diabetes mellitus, and renal disease were excluded from the study as these pathological conditions can mask hyperlipidemic abnormality of the patient.10 After explaining the limitations, written consent was obtained from all participants. The study period consisted of 90 days with fortnightly follow up visits. Name, age, sex, occupation, address, previous medication, date of follow up visit and laboratory investigations, etc of each patient was recorded on a Performa, especially designed for the study. All the base line assessments were taken on the day of inclusion (Day-0) in the study and a similar assessment was taken on Day-90 of research design. After fulfilling the inclusion criteria patients were divided in two groups, i.e.Drug-1 (3 gram of Psyllium husk) and Drug-2 (placebo capsules, containing equal amounts of partly grinded wheat) groups. Twenty hyperlipidemic patients of group-1 were provided packets containing 3 gram of Psyllium husk and were advised to take one packet thrice daily along with diet control and exercise for 40-60 minutes (brisk walk). This regimen was followed for 12 weeks.
Twenty hyperlipidemic patients of drug-2 group having borderline ‘high’ lipid profile were included in this group taken as control, and were advised to continue on isocaloric weight maintaing diet, i.e. step-1 diet and brisk walk for next three months. Patients of this group were provided capsules containing equal amount of partly grinded wheat and orange flavor, taken one capsule thrice daily after meal for three months.
Patients were advised to come in OPD, every two weeks for follow up to check blood pressure, weight, pulse rate and general appearance of the individual. Drug compliance to the regimen was monitored by interview and counseling at each clinical visits. Serum total cholesterol was estimated by the enzymatic calorimetric method (Rivelles et al 1994) using kit cat. # 303113050 by Eli Tech Diagnostic, France.10 Triglycerides were also estimated by enzymatic calorimetric method, using kit Cat. # 304710050 by Eli Tech Diagnostic. France. HDL- C was determined by using kit Cat. # 303210040 by Eli Tech Diagnostic, France. Serum LDL-cholesterol was calculated by Friedwald formula described by Davidson et al11 (LDL-Cholesterol = Total Cholesterol-(Triglycerides/5 +HDL-Cholesterol) also quoted by Delong et al (1986)12 and Beamount et al (1970).13 Data were expressed as the mean ± SD and “t” test was applied to determine statistical significance as the difference. A probability value of <0.05 was the limit of significance. RESULTS Out of 40 patients, 38 completed the over all study period. Two patients withdrew from one group (Psyllium group) due to metallic taste of Psyllium husk. Tables showing base line and post treatment values are self explanatory. When results were summed up and test parameters were compared, it was seen that, after 90 days of treatment with Psyllium, serum total cholesterol decreased from 228.27±4.89 mg/dl to 199.22±2.30 mg/dl, which is highly significant statistically (P<0.001). The overall percentage change from day-0 to day-90 was -12.72. LDL-Cholesterol level in these patients at day-0 was 159.72±5.70 mg/dl, which reduced by 90 days of treatment to 129.55±2.81 mg/dl, which is highly significant statistically (P<0.001). The overall percentage change from day-0 to day-90 was -18.88. In placebo group at day-0, the serum total cholesterol level was 215.95±2.47 mg/dl, which decreased to 208.70±5.38 mg/dl, which is non significant statistically (P>0.05).The overall percentage decrease in the parameter was -3.35. LDL-Cholesterol in placebo group at day-o was 150.75±2.67 mg/dl which reduced to 148.80±2.28 mg/dl, which is non significant statistically (P>0.05).
DISCUSSION
There are various groups of drugs which are used for the treatment of hyperlipidemia. HMG-Co reductase inhibitors (Statins), fibric acids, Niacin and psyllium hydrophilic mucilloids are important lipid lowering drugs.14 Among these lipid lowering drugs, Psyllium has its own remarkable role to decrease serum total cholesterol and LDL- cholesterol.15 In our study, serum total cholesterol decreased 12.72 % in 90 days of treatment with Psyllium husk in hyperlipidemic patients. Our study matches with the study of Anderson et al16 who observed almost same changes in serum total cholesterol and LDL- Cholesterol of 26 male patients, treated with 3.4 grams of Psyllium thrice daily for eight weeks. Our study also matches with the study of Maciejko et al17 who observed 12.00 % decrease in serum total cholesterol and 16.12 % decrease in LDL-Cholesterol in 40 hyperlipidemic patients treated with 4 grams Psyllium husk for the period of 16 weeks. He also included other parameters in his study, like body weight and systolic/diastolic blood pressure which were also significantly reduced. Our results regarding decrease in serum total cholesterol level contrasts with the results of research study conducted by Haskell et al18who observed only 6.11 % decrease in total cholesterol levels in 40 hyperlipidemic patients, when they used 2 gram Psyllium husk in 18 female patients for the period of eight weeks. This remarkable change in results may be due to changes in gender of patients, and duration of drug used. He has mentioned the mechanism of action of Psyllium husk that these Psyllium fibers stimulate bile acid synthesis in liver (7 ?-hydroxylase activity). Second mechanism, he mentioned is diversion of hepatic cholesterol for bile acid synthesis. Effect of Psyllium husk on absorption of cholesterol and fat appeared minimal but may make a small contribution to cholesterol lowering. Additional mechanisms such as inhibition of hepatic cholesterol synthesis by propionate and secondary effects of slowing glucose absorption may also play a role.19 In our study placebo group shows 3.35 % reduction in serum total cholesterol and 1.29 % reduction in LDL-Cholesterol. These results matches with the study of Spence et al20 who observed same effects of placebo given to 44 male and female hyperlipidemic patients having moderately high lipid profile. Their study shows 2.89 % reduction in serum total cholesterol and 2.21 % reduction in LDL-Cholesterol. Results of research study conducted at Lipid Research Centre held by Levy et al21 do not match with our results of research. They observed 5.98 % and 9.97 % reduced levels of serum total cholesterol and LDL-Cholesterol, respectively, in 109 hyperlipidemic patients treated by Psyllium husk 3 gram daily for the period of 24 weeks. Their study was double blind placebo controlled. These changes in results may be due to double blind research design, large sample size and environmental factors like in that study all hyperlipidemic patients were admitted at Lipid Research Centre, so were closely observed and advised for brisk walk and to take controlled step-1 diet.22 Drug compliance between our and their study was same, i.e. in our study patients discontinued taking Psyllium due to its metallic taste. In their study 11 patients discontinued to take Psyllium fibers, mostly due to same reasons of its metallic taste. Another study conducted by Kane et al23 also contradicts with our study as they observed only 12.22 % reduction in LDL- Cholesterol when 3 gram Psyllium husk was administered in 14 female hyperlipidemic patients above the age of 40 years. Our study proved 18.88 % reduction in LDL-Cholesterol levels which is much higher than 12.22 %. Change in these results may be due only female gender and age which was specifically above 4o years. Our study comprised of both male and female hyperlipidemic patients with age range between 21-60 years.
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