Cameroon doctor studies varieties of ‘good cholesterol’ in Jerusalemites

Certain HDL particles seem to protect better against atherosclerosis.

By JUDY SIEGEL
Updated: AUGUST 3, 2016 23:50
DR. CHOBUFO DITAH (left) with Prof. Jeremy Kark, under whom he wrote his master’s thesis in the International Master’s of Public Health program. (photo credit: HEBREW UNIVERSITY)
DR. CHOBUFO DITAH (left) with Prof. Jeremy Kark, under whom he wrote his master’s thesis in the International Master’s of Public Health program.
(photo credit: HEBREW UNIVERSITY)
A doctor from Cameroon who is studying at the Hebrew University suggests a reassessment of what types of “good cholesterol” actually protects against the clogging of coronary arteries and heart attacks.
The research, which involved hundreds of Jews and Arabs living in Jerusalem, was carried out by Dr. Chobufo Ditah as his thesis in the International Master’s of Public Health program, under the direction of the Prof. Jeremy Kark of the HU-Hadassah Braun School of Public Health and Community Medicine.
The idea that plasma high-density lipoprotein cholesterol (HDL-C) is protective against coronary heart disease has been part of medical conventional wisdom for 50 years. HDL-C has traditionally been considered the most important component of so-called “good cholesterol” HDL. However, drug studies that raised levels of HDL-C have failed to support a causal role for the amount of cholesterol carried in HDL in reducing the risk of coronary heart disease, Ditah said.
With advances in the separation of lipoproteins by size and functionality, research has managed to identify specific types of HDL that seem to be better predictors of coronary heart disease than the traditional HDL-C. Recent evidence suggests that small, dense, protein-rich particles in HDL may be more atheroprotective than large, buoyant cholesterol-rich particles.
To explore this, he and colleagues recruited for the study 274 Arabs and 230 Jews living in Jerusalem. The researchers used nuclear magnetic resonance (NMR) spectroscopy to identify the numbers and sizes of plasma HDL particles and helical CT-scanning to identify calcification in their coronary arteries, reflecting the overall burden of coronary atherosclerosis. With these data, they looked for connections between the concentrations and sizes of different HDL particles and coronary artery calcification.
Their findings, just published in the prestigious journal Atherosclerosis, showed a statistically significant inverse association of both the number of HDL particles (HDLP) and the concentration of small and medium-sized HDL particles (MS-HDL-P) with coronary artery calcification, after adjusting for age, taking statins, smoking and other factors. There was no association between large HDL-P and coronary artery calcification in either population group.
The association with HDL-C was weaker and inconsistent between men and women.
“Our findings indicate that HDL-P and MS-HDL-P are better independent markers of coronary artery disease, as reflected by coronary artery calcification, than HDL-C, at least in this bi-ethnic population of Israelis and Palestinians,” said Ditah.
“With a better understanding of HDL’s complexity and a better ability to measure its components, it is now possible to move past HDL-C to more refined measures that better reflect HDL’s role in coronary heart disease risk.
Based on the accumulating evidence, incorporation of MS-HDL-P or HDL-P into the routine prediction of coronary heart disease risk should be considered,” Kark recommended.
“These findings support previous reports, based on studies in other population groups, suggesting that small dense HDL particles are protectively associated with risk of coronary heart disease. The consistency of this finding in a new population of urban Arabs and Jews, using different disease outcomes and different separation methods, add more strength to those findings,” added Ditah.
He was born and raised in a small village called Mankon in northwest Cameroon. He earned his MD degree with honors from the Faculty of Medicine and Biomedical Sciences at the University of Yaoundé I in Cameroon before moving on to earn full certification in the US. He also holds a master’s of public health degree (magna cum laude) degree from HU, graduating as best overall student in his class and receiving the award of excellence in a master’s of science thesis from the Faculty of Medicine. He credits the Pears Foundation in the UK for making it possible for him to study in HU’s IMPH program.
Ditah currently serves as a medical referent with the humanitarian NGO Doctors Without Borders and oversees the implementation, evaluation and reorientation of medical interventions in host countries. He has worked in several African countries including South Sudan, Chad, Cameroon and Central African Republic. He also served as a chief medical officer in Cameroon for more than four years, implementing major public health interventions in HIV/AIDS, tuberculosis and vaccinations in local communities as well as directing hospitals.
He says he looks forward to earning a doctorate in epidemiology before settling down to a full-scale research and teaching career.
The International Master’s of Public Health program degree has been awarded to more than 800 graduates from 92 developing countries in Africa, Asia, Latin America and Eastern Europe, as well as from developed countries of North America and Western Europe. The comprehensive multi-disciplinary, year-long training experience prepares graduates to take up key positions as leaders and teachers of public health in their home countries and to initiate and participate in the promotion and development of public health practices and develop capacity-building programs for training public health personnel.