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Triglycerides and APIOE4

Posted: Thu Aug 22, 2019 8:34 pm
by Karina52
What are thoughts on this study which showed lower triglycerides had higher AD incidence in E4s ? This has me stumped.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860622/

Re: Triglycerides and APIOE4

Posted: Fri Aug 23, 2019 7:41 am
by BrianR
I wonder about the statistical power, given that n only equals 14 for ε4+AD.

Given the authors had previously "... found no association between possession of the APOE-ε4 allele and AD in Yoruba residing in Nigeria" might also lead us to speculate that Yorubans living at the equator may utilize blood lipids/APOE differently than those of European descent living in the temperate zones (who seem to constitute the majority of most studies).

I'd say it's an interesting data point, but I'd prefer larger studies done more recently.

Re: Triglycerides and APIOE4

Posted: Fri Aug 23, 2019 9:46 am
by Roamingseer
The mean cholesterol and LDL for the AD groups were higher than the normal groups for individuals without APOE-ε4 (cholesterol p = 0.041, LDL p = 0.035), but not for individuals with APOE-ε4. A rather different trend was seen for the mean triglycerides. The mean triglycerides for the AD groups was lower compared to the normal groups for individuals with APOE-ε4 (p < 0.001), but not for individuals without APOE-ε4. There was no difference for the mean HDL between the AD and the normal groups, with or without APOE-ε4.
When looking at the data, the first sentence makes sense: NAPOE4 +TC, +LDL --> AD, whereas APOE4 -TC, -LDL --> AD. The second and third sentence is a little confounding, but means: NAPOE4 TG are not correlated to AD, whereas APOE4 -TG --> AD (same as TC, LDL above). Also, In the AD APOE4 group, the average age is 79.7yrs vs 75.9yrs to the APOE4 Normals. What if the APOE4 individuals that are getting closer to 80yrs of age with higher TC, higher LDL, and higher TG are simply dying of other causes, i.e., arteriosclerosis before they get AD? The paper appears to address this with this...
The study sample had a small number of AD cases (29 subjects) and will require confirmation once a larger number of subjects become available. Most of the attrition of the 1992 cohort was due to death, raising the possibility of survivor bias. However, the possession of the APOE-ε4 allele was not associated with mortality risk in this cohort.44
I wonder what the TC, LDL and TG for APOE4 Normals, which are age adjusted to 79.7yrs as the APOE4 AD group, would be.

I have read in several areas, including Dr. Greger's Nutrition Facts, that in Africa APOE4 is not associated with higher risk for Alzheimer's. Diet, exercise and social factors (stress) must also factor in. This exercise makes me want to take a statistics class!

Re: Triglycerides and APIOE4

Posted: Sat Aug 24, 2019 4:35 am
by dpnelson
I have not read the article, but I wonder if the correlation of higher triglycerides to AD is actually caused by increased alcohol consumption which could cause the higher triglycerides.