Continued from page 44
Preston/Stokes have several times challenged the obesity
paradox, most recently in suggesting that looking at weight
change over time (as opposed to weight at a single point
in time) lowers the predictive power of obesity and makes
overweight and obesity appear less harmful than they really are.5 Can you respond to this challenge?
Confounders are probably important considerations, but many
studies show the obesity paradox after correcting for leading
confounders. Also non-purposeful weight loss is probably a
bad thing and is associated with high risk, and the Stokes/
Preston papers do not differentiate purposeful from nonpurposeful weight loss.
The perfect case would be long-term lean and fit. However, this is not very helpful for the 75% of society and our
patients who are sitting in front of us now being overweight
or obese (currently, obesity is present in 36% of U.S. adults).
Would Preston and Stokes suggest that the obese not lose
weight? This is their highest risk group: those who were previously heavier and now have lower weight.
For the patients we see on a daily basis, I think it is
much more important and helpful to give the messages
and advice I’ve already discussed. And although the data
from Stokes and Preston may have some accuracy, it does
not at all help us care better for our many patients who are
currently carrying 20, 30, or even 40 extra pounds, whereas
the advice from my research could be very useful.
REFERENCES:
1. Lavie CJ, Osman AF, Milani RV, Mehra MR. Am J Cardiol.
2003;91:891-4.
2. Wang ZJ, Zhou YJ, Galper BZ, Gao F, Yeh RW, Mauri L. Heart.
2015;101:1631-8.
3. Lavie CJ, De Schutter A, Milani RV. Heart. 2015;101:1610-1.
4. Tomiyama AJ, Hunger JM, Nguyen-Cuu J, et al. Int J Obes
(Lond). 2016 Feb. 4. [Epub ahead of print]
5. Stokes A, Preston SH. Proc Natl Acad Sci USA. 2016;113:572-7.
Related Research
Telomeres Go Both Ways
Telomere shortening is involved with all aspects of the aging
process on a cellular level. Lifestyle factors including smoking, unhealthy diet, and lack of exercise appear to increase
the pace of telomere shortening. Obesity also contributes
to telomere attrition, although a causal relationship has not
been established.1 On the flip side, the Mediterranean diet
has been associated with longer telomere length.2 But a
new study in the International Journal of Obesity showed
that telomere length actually increased after weight loss
induced by bariatric surgery.3
Investigators followed 142 bariatric surgery patients for
more than 10 years, using normal weight individuals matched
by age and sex as controls. “During 10 years of pronounced
and sustained weight loss, relative telomere length increased
by 0.024 ± 0.14 (p = 0.047) in bariatric patients (aged 29-79
years),” wrote Laimer et al. Telomere length decreased from
baseline over the same period in the controls.
bama at Birmingham investigators reported
for the first time an association between
verapamil use and lower fasting glucose
levels in humans with diabetes.6 (They previously showed that verapamil completely
reverses the disease in mice models.)
They evaluated 5,000 adults with diabetes who were part of the National Institutes of
Health-sponsored REGARDS study (Reasons
for Geographic and Racial Differences in
Stroke). Calcium-channel blocker (CCB) users
had 5 mg/dl lower serum glucose compared
to nonusers and verapamil users had on
average 10 mg/dl lower serum glucose
compared to CCB nonusers. The effect was
strongest for verapamil users who took
insulin alone to manage their diabetes; they
showed a 37 mg/dl lower serum glucose.
A Diabetes/AF Conundrum
One to the Gut
We mentioned atrial fibrillation as it relates to obesity and
why diabetes is an important CV ‘multiplier’ of risk. In the
January 26, 2016, issue of JACC, Ashburner et al. looked
at diabetes and stroke risk.4 Diabetes is usually considered
a dichotomous measure that uniformly appears as a risk
marker in risk scores. The authors explored the duration of
diabetes, the extent of diabetes control, and the likelihood
of ischemic stroke among persons with diabetes and AF during periods when the observed population was not receiving
warfarin. They found that individuals with AF who have had
diabetes for 3 or more years had 1.74-fold more strokes than
those with diabetes of shorter duration, while event rates
were similar among diabetic persons with HbA1c < 7%, 7% to
8.9%, and > 9%.
Their findings suggest that glycemic control is not
relevant to macrovascular event rates, while non-glycemic
factors are present among persons with diabetes and have
progressively greater effect with increasing time. As you
might imagine, this is controversial, so for a further perspective, read the accompanying commentary by Bloomgarden
and Bansilal.5
The contribution of the gut microbiota
(intestinal bacterial strains) in the developContinued on page 54
TABLE
Pathogenic Gut Flora in HC and CHF Patients
Candida
Campylobacter
Shigella
Salmonella
Yersinia
enterocolitica
% of patients having pathogens in stool
HC
8
12
16
0
0
Total CHF
33.3
79.1
37.5
38.7
32.8
NYHA I to II
8.9
58.4
33.3
41.2
33.6
NYHA III to IV
92.0
96.3
40.5
36.2
32.0
Colony-forming units/ml (×105) of stool
HC
0.8 ± 0.4
1.0 ± 0.3
1.6 ± 0.2
0
0
Total CHF
21.3 ± 1.6∗
85.3 ± 3.7∗
38.9 ± 12.3∗
31.3 ± 9.1∗
22.9 ± 6.3∗
NYHA I to II
NYHA III to IV
2.9 ± 1.1
8.3 ± 1.3†
7.9 ± 1.7†
20.2 ± 4.9∗
23.1 ± 5.9∗
37.2 ± 4.4∗‡
164.0 ± 6.1∗‡
70.4 ± 17.2∗‡
37.6 ± 13.1∗
24.8 ± 7.5∗
Verapamil Lowers Glucose Levels
*p < 0.001, total patients with chronic heart failure (CHF) vs healthy control: subjects (HC), NYHA III to IV versus HC. †p < 0.01, NYHA I to II versus HC. ‡p <
0.001, NYHA III to IV versus NYHA I to II. ‡p < 0.01, NYHA III to IV versus NYHA I to II.
As this issue of CSWN was going to press, University of Ala-
NYHA = New York Heart Association.
52
CardioSource WorldNews
March 2016