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CURRENT TOPICS
SA JOURNAL OF DIABETES & VASCULAR DISEASE
78
VOLUME 8 NUMBER 2 • JUNE 2011
function.
17
Flatt
et al
. recently (2009) documented studies in which
long-term glycaemic control had been recorded following bypass
and restriction bariatric surgery in obese type 2 diabetic patients.
17
Taking into account what is mentioned above and that there are
mechanisms which are independent of weight loss that contribute
to diabetes control (reduced appetite and increased satiety, and
incretin effect), it is theoretically plausible to consider surgery as an
alternative or complementary therapy to medical treatment of type
2 diabetes, even in patients with lower BMIs than conventionally
accepted for bariatric surgery.
In recent years several groups have published encouraging
results of their early experiences of metabolic surgery (novel and
established techniques) in diabetic patients with BMI
<
35 kg/m
2
.
47-50
The authors have noted how difficult it was to treat these patients
with type 2 diabetes in current clinical practice. following a
complete evaluation and informed consent, 19 non-obese
diabetic patients have undergone surgical treatment and at the
time of writing, results are promising (unpublished data). Table
3 summarises our early observations from patients for whom we
have one-year follow-up data. Fig. 2 shows the criteria we followed
to select patients. Bariatric surgery is widely accepted for type 2
diabetes and BMI
>
35 kg/m
2
. If BMI is
<
35 kg/m
2
we consider
surgery in the presence of the metabolic syndrome. In the absence
of metabolic abnormalities, further assessments are needed to rule
out autoimmunity (suggestive of type 1 diabetes) and poor beta-
cell reserve. Patients with negative GADA and ICA, and C-peptide
>
1.0 ng/ml qualify for surgical treatment: laparoscopic duodeno-
jejunal bypass. Otherwise, surgery is contraindicated.
It shouldbe stressed, however, that except for the study of Dixon
et
al
.
24
these initial clinical experiences are limited to a small number of
patients and short-term follow-up, and have lacked a control group.
Conclusion
Bariatric surgery is an effective intervention to treat extremely
obese patients, improving not only body weight but diabetes
and the metabolic syndrome as well. since some mechanisms are
weight loss independent, several groups have started performing
surgical treatment in diabetic patients who have mild obesity or
even overweight, with encouraging metabolic results.
These early experiences must be considered preliminary
observations. Assessment of the real impact of surgical interventions
on metabolic disorders in patients who are not extremely obese
will require well designed randomised prospective studies that
include not only a higher number of patients and a longer follow
up, but also a non-surgical group treated with intensive lifestyle
interventions and newer pharmacological agents with the potential
for beta-cell preservation (i.e. thiazolidinediones, incretin therapies).
Key messages
•
Bariatric surgery reduces excess body weight and improves
type 2 diabetes and symptoms of the metabolic syndrome
•
In type 2 diabetic patients with BMI < 35 kg/m
2
bariatric
surgery has delivered encouraging preliminary results
Table 2.
Degree of obesity in landmark clinical trials. Type 2 diabetic
patients are overweight or mildly obese and have abdominal
adiposity.
Trial
Duration of
diabetes (years)
BMI
(kg/m
2
) Waist circumference
UKPDS 34
39
Newly diagnosed 31.4 No data
ADOPT
40
≤
2
32.2 105.5 cm (both sexes)
ADVANCE
41
8
28.5 99.1 cm (both sexes)
4-T
42
9
29.8 103 cm (males) 98 cm (females)
ACCORD
43
10
32.2 106.8 cm (both sexes)
VADT
44
11.5
31.3 No data
ACCORD
=
Action to Control Cardiovascular Risk in Diabetes; ADOPT
=
A
Diabetes Outcome Progression Trial; ADVANCE
=
Action in Diabetes and
Vascular Disease: Preterax and Diamicron Modified Release Controlled
evaluation; 4-T
=
Treating to Target in Type 2 Diabetes; UKPDS 34
=
UK
Prospective Diabetes study 34; VADT
=
Veterans Affairs Diabetes Trial
Table 3.
Early results of metabolic surgery in 11 non-obese (BMI
<
30kg/
m
2
) patients with a mean duration of type 2 diabetes of five years
(range 1 to 10). The mean age was 45 years (range 35 to 54) and
follow-up was one year
Pre-surgery
One year post-surgery
BMI
28.7 kg/m
2
27.6 kg/m
2
Fasting plasma
glucose
9.2 mmol/l
5.7 mmol/l
(165 mg/dl)
(103 mg/dl)
HbA
1c
8.3%
6.1%
Pharmacological
therapy
Monotherapy (
n
=
2)
Combined therapy (
n
=
7)
Insulin (
n
=
2)
No drugs (
n
=
2)
Metformin (
n
=
7)
No or less insulin (
n
=
2)
BMI
=
body mass index; HbA
1C
=
glycated haemoglobin A
1c
Figure 2.
Selection criteria for bariatric/metabolic surgery in type 2
diabetic patients.
BMI
=
body mass index; GADA
=
glutamic acid decarboxylase antibodies;
HbA
1c
=
glycated haemoglobin A
1c
; ICA
=
islet cell antibodies
C-Peptide
gada/ica
others
metabolic
syndrome
medical therapy
follow up
consider
surgery
no
patient qualifies
patient does
not qualify
yes
yes
no
BMI
HbA
1C
7.0 – 8.5%
<
35
≥
35
