Download When to start ACE inhibitors in type 2 diabetes

CLINICAL CASE REVIEW
MANAGEMENT PROBLEMS IN GENERAL PRACTICE
When to start ACE inhibitors
in type 2 diabetes
Commentary by PETER COLMAN, MB BS, FRACP, MD
What should be done
in this case?
So, what should be recommended for
our patient with well-controlled diabetes who has no microalbuminuria?
He should have three-monthly
• C a s e scenario
creatinine rises. If the diabetes is
untreated, progression to end-stage HbAlc measurements, with target of
A 54-year-old man has had type 2 renal failure is likely over the next <7%. The combination of insulin and
metformin can be very effective in
diabetes for four years. It is well con- five years.
trolled with insulin and metformin.
Type 2 diabetes may remain undi- these patients. The new glitazone
Currently, he has no albuminuria. At agnosed for many years, and patients agents - rosiglitazone and pioglitawhat point and how should I start often present with microalbuminuria zone - may also be effective in
ACE inhibitors to prevent renal dis- or even overt proteinuria at the time patients with type 2 diabetes in combination with insulin.
ease?
of diagnosis.
His blood pressure should be
In the management of diabetic
checked
regularly. If it is consistently
nephropathy the main targets of
Commentary
intervention are glycaemic control, above a target of 130/85mmHg, he
should be started on an ACE
This is an important clinical ques- blood pressure and hyperlipidaemia. inhibitor.
Monitoring
of
urinary
albumin
excretion. The prevalence of type 2 diaHis lipid levels should be checked
betes is increasing at an alarming tion rate, protein excretion and at least 12-monthly, with the followglomerular
filtration
rate
provide
rate. In many countries, including
ing targets: total cholesterol,
South Africa, people are developing information about the rate of decline <5mmol/l; triglyceride, <2,0mmol/l;
of
renal
function.
type 2 diabetes at a younger age and
In both type 1 and type 2 diabetes, and HDL, >lmmol/l.
are likely to have diabetes for longer
Every 12 months he should have a
the
rate of increase of the albumin
and be at risk of developing all the
excretion rate correlates with glyco- test for microalbuminuria. Initial
complications of diabetes.
sylated haemoglobin (HbAlc). screening can be performed on early
Several trials have shown that inten- morning urine samples using either
General principles
sive glycaemic control (HbAlc target, an albumin:creatine ratio (normal,
Prevention of diabetic nephropathy 7%) reduces development of microal- <3mg/mmol in males, <3,5mg/mmol
requires knowledge of its natural his- buminuria by 40%. It is unclear to in females) or a semiquantitative diptory. It is generally thought that 20 what degree secondary intervention stick technique. Elevations should be
to 30% of patients with diabetes with intensified control can reverse confirmed with timed overnight coldevelop nephropathy and that this existing nephropathy.
lections or a 24-hour urine sample. If
may be genetically determined. In
The sixth report of Australia's microalbuminuria is detected, an
those patients developing nephropa- Joint National Committee on ACE inhibitor should be introduced
thy there is a characteristic evolu- Prevention, Detection, Evaluation even in the absence of hypertension,
tion. The first detectable change is and Treatment of High Blood with a target blood pressure of
glomerular hyperfiltration that can Pressure has suggested that blood
125/75mmHg.
be evident shortly after diagnosis. pressure should be reduced to
Currently, there are no prospective
After five to ten years of diabetes,
130/85mmHg in patients with dia- data to support the long-term use of
microalbuminuria (albumin excretion betes, with the preferred agents for
an ACE inhibitor prior to developrate, 30 to 300mg per 24 hours) is treatment being ACE inhibitors.1 In ment of microalbuminuria in the
detectable. Usually by this time the patients who have proteinuria, the absence of hypertension. A trial
blood pressure has become elevated. recommended target blood pressure recently presented in abstract at the
After another five to ten years, overt is 125/75mmHg.
American Diabetes Society annual
proteinuria (>500mg protein per 24
Finally, microalbuminuria and pro- scientific meeting has shown that
hours) develops, the glomerular filtration rate begins tofell, and serum teinuria have been shown to be inde- treatment with an angiotensin receppendent risk factors in increasing the tor blocker may reduce the progresrisk of cardiovascular mortality. sion of nephropathy in patients with
Thus, patients with microalbumin- type 2 diabetes. It is likely that once
uria or proteinuria should have vigor- this study is formally published there
ous reduction of other cardiovascular will be an evidence base for considerAssociate Professor Coiman is Director,
risk factors (smoking, hyperlipid- ing the use of angiotensin receptor
Department of Diabetes and
blockers in patients with type 2 diaEndocrinology, Royal Melbourne Hospital, aemia) and should be treated with
Parkville, Australia.
aspirin.
betes and microalbuminuria. •
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
In the middle-aged man who has had type 2 diabetes for four
years, when and how should ACE inhibitors be started to prevent
renal disease?
References available on request.
MODERN MEDICINE OF SOUTH AFRICA / MAY 2003