Recently, the NY Times had a news article based on a research
study that compared twins, one of which exercised and one that
didn't, to see whether they differed on measures of physical
response and on measures of brain anatomy. The NY Times
article can be accessed here:
http://well.blogs.nytimes.com/2015/03/04/one-twin-exercises-the-other-doesnt/?alg=4H7RR
The abstract for the research article is on PubMed; see:
http://www.ncbi.nlm.nih.gov/pubmed/25003773
NOTE: There is the annoying use of P-values instead
of actual test values which makes the abstract a good
example of how NOT to report statistical results.
And the reference for the study is as follows (APA format
as scholar.google.com understands APA format, which
means that it is APA-ish):
Rottensteiner, M., Leskinen, T., Niskanen, E., Aaltonen, S.,
Mutikainen, S., Wikgren, J., ... & Kujala, U. M. (2014). Physical
Activity, Fitness, Glucose Homeostasis, and Brain Morphology
in Twins. Medicine and science in sports and exercise. 47(3),
509-518.
doi: 10.1249/MSS.0000000000000437.
The results are pretty much what one would naively predict,
namely, the twin that exercises differs from the twin the doesn't
exercise on a number of physical measures and on brain
measures. There are a few issues that raise some concern:
(1) The twins came from a Finnish database (the "FinnTwin16
Cohort"; mean age 34.0 years at the time of the study). In the
latest wave of the study, N=4183 twins (1880 males) from which
202 male MZ pairs were selected. A process of elimination
resulted in *N=10* pairs that met inclusion criteria and these
10 pairs served as participants in the study. In the published
article, Figure 1 provides a flowchart of the process of going
from the initial 202 twins to the final 10 twins. One is left with
the question of which population the results of this study generalize
to (e.g., male twins who differ in level of exercise and have time
to participate in the study?).
(2) The key question here, I think, is if genetically identical
individuals
(males) differ in their level of physical activity, do they develop
different risks for later illnesses (e.g., cardiovascular, diabetes,
etc.)?
The results seem to suggest that it may, in other words, environmental
factors trump genetic factors. But this is a overly simplistic view
of things and the small sample size should make one very cautious.
This is one of those areas where replication of results will play
a very important role.
-Mike Palij
New York University
[email protected]
---
You are currently subscribed to tips as: [email protected].
To unsubscribe click here:
http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=43263
or send a blank email to
leave-43263-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
