VOLUME 10 NUMBER 2 • JUNE 2013
75
SA JOURNAL OF DIABETES & VASCULAR DISEASE
CONFERENCE REPORT
Nonetheless the major problem remains the lack of implementa-
tion of known therapies.
Exercise and fitness in diabetes and heart disease – when do
we reach the limits?
Carl Lavie, John Ochsner Heart and Vascular Institute, New Orleans
Cardiorespiratory fitness is graded: low fitness is defined as the
lowest quintile of individuals assessed according to their time on
treadmill adjusted for gender and age. Small improvements in fitness
result in a significant reduction in incidence of diabetes and mortality.
Physical inactivity and low fitness increases total mortality by 1.7-2X in
males. Fitness overrides fatness as a cause of cardiovascular disease.
There are multiple mechanisms mediating the effect of fitness. An
important factor is improvement in mood and anxiety. The exercise
dose is important, more not necessarily being better. Resistance
training is important in addition to aerobic exercise. 40 minutes / day
of vigorous exercise probably provides the maximal benefit.
Modern drug therapy for Type 2 diabetes: a cardiology
perspective
Mansoor Husain, Toronto General Hospital Research Institute
The DECODE study showed that IGT increases mortality risk.
HbA1C has been shown to correlate with macrovascular disease
and heart failure. Reducing HbA1C has not been shown to change
this outcome. Good glycaemic control improves quality of life and
microvascular disease. Meta-analysis of sulphonylureas showed
that they increase in mortality 2.5-3X. There is no convincing data
on survival for any other hypoglycaemic therapy.
GLP-1 is rapidly degraded (2½ min), thus only a small proportion
reaches the heart. GLP metabolites may be the active substances
affecting cardiovascular function. Experimental evidence has
shown that DPP4 inhibition and GLP1 agonism improve survival in
mice after MI. GLP1 agonism but not DPP4 inhibition has reduced
experimental infarct size.
The Hatter Lecture:
Blood pressure control in diabetes: what are the limits, what
are the drugs and how are they defined?
Morris Brown, University of Cambridge, UK
Brown discussed the control of hypertension in diabetics, pointing
out that in all hypertensives, the risk for MI is greater than that
for stroke, although the less linear relationship of BP to stroke
makes it easier to detect changes in the frequency of stroke than
of MI when BP is reduced. Masked hypertension occurs more
frequently in diabetics and carries a risk equivalent to that of Stage
1 hypertension. Treating BP to target level in diabetics does not
restore the CV risk to that of normotensive (untreated) diabetics.
Brown has found evidence of primary hyperaldosteronism in
hypertensives. This may be identified by inappropriate suppression
of the renin level. Hypokalaemia is found less frequently. About
10% of this group have adrenal microadenomas which may be
identified by PET scanning. Early identification and excision may
cure the hypertension but is less likely to be effective in those
whose blood pressure elevation is long-standing.
Sunday morning debate:
Diabetologist: The major aim in the therapy of DM2 lies in
limiting microvascular damage vs. Cardiologist: the major aim
in the therapy of DM2 lies in limiting macrovascular damage
Steven Kahn (Diabetologist) University of Washington, Seattle
The 10-year mortality rate was 40% in UKPDS. The mortality
in diabetes is lower in a high income group of patients. In the
high income group, the expenditure on diabetes far exceeds the
expenditure in middle and lower income groups. Around 50% of all
cause mortality in diabetes is non-cardiovascular. The combination
of diabetes and chronic kidney disease has an all cause mortality of
30% compared to 7.5% in a group in whom neither condition is
present. Similarly the combination of CKD and albuminuria has a
mortality of 47% compared to those with neither condition. The
10-year results of UKPDS showed reductions in both mortality
and MI. In the ACCORD study, although negative overall, better
results were obtained in the subgroups with albuminuria. The most
recent NHANES report on diabetics found worsening percentages
of glycaemic control, BP control, control of LDL cholesterol and
diminishing numbers on statin therapy, with a very low percentage
of patients achieving control of all these parameters.
Bryan Williams (Cardiologist), University College London
Increased pulse pressure develops with ageing and begins earlier in
diabetes. The presence of an increased pulse pressure in diabetes is
strongly correlated with mortality. The pathogenesis involves loss
of elastin, collagen deposition and modification of the collagen by
advanced glycation end-products which result in cross linkage of
collagen, aortic stiffness, loading of the left ventricle and a reduced
work capacity. In diabetics there is a loss of the reflected wave
in the aorta with transmission of pulsatile flow more distally in
the peripheral circulation. This leads to increased pulsatility in the
microcirculation and promotes microvascular disease. Diabetes
differs from the effects seen in hypertension and ageing in that
autoregulation within the microcirculation is impaired.
Beyond warfarin – are there any limits?
Stefan Hohnloser, JW Goethe University, Frankfurt
The results of the RE-LY, ROCKET-AF and ARISTOTLE trials were
reviewed. Given the reduced stroke risk, diminution in intracranial
bleeding and ease of use, Hohnloser preferred the use of one of
the novel oral anticoagulants to warfarin, although admitting
that cost constraints were problematic. His preference overrode
considerations of good control of the INR on warfarin or moderate
chronic kidney injury (GFR 30-60 ml/min).
Monday morning:
Debate: Life style changes vs. drugs – which best limits
cardiovascular disease?
Timothy Noakes, University of Cape Town and Peter Libby, Brigham
& Women’s Hospital, Harvard Medical School, Boston
The debate between Timothy Noakes and Peter Libby was an
excellent closing event, both arguing well. Noakes proposed that
life style with increased exercise and a low CHO diet could in his
view achieve excellent results on general health including levels of
blood glucose and lipids. Thus drug therapy could often be avoided.
However, no controlled studies were presented. Libby agreed that
the standard low fat diet recommendation was not the best. He
gave his support to the Mediterranean diet (fresh vegetables,
high fruit, fish rather than meat, nuts and olive oil). In the first
controlled outcome diet study ever (New Engl J Med, April 2013),
the Mediterranean diet decreased CV outcomes and total mortality
compared with low fat. However, Libby argued, the major problem
with any diet was poor long term adherence, less than 40% at one
year, so that in clinical practice drug therapy was more effective.
