Todd,

In regards to thyroid function:  Have you tested your basal temperature?
 T3,T4, and TSH can be normal eventhough an individual is hypothyroid.  The
only definitive test is to check yur temperature 3-4X/day for a few days,
starting when rising in the morning, then average the results.  An ave. below
98 degrees could indicate a sluggish thyroid, and this could adversely effect
your lipid profile.

DHEA, testosterone, androstendione, and other hormones decline with age.  A
problem with cholesterol metabolism may cause these hormones to be
prematurely lowered.  This may be one mechanism as to why cholesterol levels
tend to rise as one ages.

Thank you for the Journal reference on aerobic exercise.  Aerobic exercise,
indeed, has positive benefits on blood lipid profiles, but so does resistance
training ( see: Eaton, The Paleolithic Prescription, pp. 193-194).  In
addition, resistance exercise will increase lean muscle mass (LBM).  While
metabolic rate will stay elevated for 1-3 hrs. following aerobic training,
your metabolic rate will stay elevated 24 hr./day if you can increase your
LBM.  Resistance training can also positively influence levels of
testosterone and growth hormone.  A combination of aerobic and anaerobic
(resistance) exercise is optimal, and closely resembles the activity patterns
of our paleo ancesters.

Maintaining youthful levels of LBM and hormone levels are the cornerstones of
anti-aging medicine.

Ed Campbell, DC, CSCS