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98
VOLUME 8 NUMBER 2 • JUNE 2011
REPORTS
SA JOURNAL OF DIABETES & VASCULAR DISEASE
Neglected topics in diabetes care: a Novo Nordisk-
sponsored symposium at the 2011 SEMDSA congress
T
his Novo Nordisk-sponsored symposium,
the seventh in the series, focused on
‘neglected topics in diabetes care’. Although
well attended, the sponsors are very aware
that many diabetes healthcare professionals
would have liked to share in this annual update
event, but for a variety of reasons, were not
able to do so.
The
South African Journal of Diabetes and
Vascular Diseases
has prepared this report
with assistance from both organisers, Dr W de
Lange and Prof W Mollentze, highlighting key
aspects of the lectures.
LIFE-THREATENING INFECTIONS IN
DIABETES
Dr Peter Smith, microbiologist, Ampath,
Bloemfontein
Placing infections in diabetic patients in per-
spective, Dr Smith pointed out that prior to the
availability of insulin and antibiotics, patients
died from their infections. ‘Today we believe
diabetics are at increased risk of infection, but
this is not supported by strong evidence. The
relationship between glycaemic control and
infections is not well established, although
diminished immunity as a contributor to rate
and extent of infections is plausible.’
Infections associated with diabetes
Urinary tract infections
These infections are often more severe in
diabetes; recurrence and rarer complications
occur more frequently in diabetic patients.
Reasons for increased susceptibility in dia-
betics are due to autonomic neuropathy caus-
ing urinary retention and stasis, with increased
potential for bacterial growth. Phagocyte func-
tion is depressed. Antibiotic penetration into
tissues is likely to be reduced in diabetics.
Pyelonephritis occurs with greater fre-
quency and severity in diabetic patients.
Peri-nephric abscesses are caused by
E coli
as part of ascending urinary tract infections
(80%) or
Staphylococcus aureus
from a distant
site. This diagnosis is confirmed by sonar/CT
scan. Surgical drainage is essential with appro-
priate antimicrobial (AMB) treatment.
Emphysematous nephritis/pyelonephritis
occurs primarily in diabetic patients (90% of
cases) and if this condition does not respond
to treatment, the focus should shift to other
complications (such as the development of a
peri-nephric abscess or papillary necrosis).
Increased skin infections
Candida albicans
is a frequent problem in 80
to 88% of diabetic patients, probably due to
the fact that there is a glucose-induced pro-
tein that promotes adherence to the buccal or
vaginal epithelium. Other conditions such as
necrotising fasciitis occur and require aggres-
sive debridement and appropriate antibiotics.
Surgical-site infections
Diabetics are exposed to an increased risk of
surgical-site infections, but good glucose con-
trol can reduce this risk. Extra care needs to
be taken to prevent these infections in dia-
betic patients. If they occur, treatment must
be guided by tissue culture, remembering the
high likelihood of very resistant organisms as a
cause of hospital-acquired infections.
Respiratory tract infections
Pneumonia results in higher mortality in dia-
betic patients. They have a six-fold higher
relative risk of hospitalisation in ’flu epidem-
ics due to
Staphylococcus
-related pneumonia.
The metabolic complications of the pneumonia
can be severe.
Diabetes and tuberculosis (TB)
Diabetics respond appropriately to TB medica-
tion, but have a 50% increased mortality from
TB compared to non-diabetics. INH aggravates
peripheral neuropathy and should be sup-
plemented by pyridoxine to prevent this side
effect.
Infections that are life threatening
and occur almost exclusively in
diabetics
Malignant/invasive otitis externa
Primarily due to
Pseudomonas aeriginosa
, this
infection can be life threatening. As it may
cause neither fever nor pain, there is frequently
Reasons for increased risk of infections
• reduced immune response
• vascular insufficiency
• peripheral neuropathy reducing sensory
awareness
• autonomic neuropathy
• skin and mucous colonisation with pathogenic
organisms such as
Staphylococcus aureus
and
Candida
species.
Take-home message
•
Treat diabetics with appropriate
antibiotics for a longer period of
time (7–14 days) and check that
treatment has been successful as
resistant organisms occur more
frequently in diabetic patients.
•
Routine imaging of the renal tract
in diabetics with pyelonephritis is
recommended to ensure there is no
added complication or obstruction.
•
In urinary tract infections, all
attempts should be made to culture
organisms to guide AMB therapy.
Cure needs to be confirmed, as
resistant strains will complicate
future therapy.
Take-home message
• It is important to vaccinate diabetic
patients against ’flu as there is
increased morbidity and mortality
among them during influenza
epidemics.
Take-home message
• Use quinolones sparingly and with
utmost care for pneumonia in a
high TB-risk environment, as it can
result in a missed TB diagnosis.
