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SA JOURNAL OF DIABETES & VASCULAR DISEASE
REVIEW
VOLUME 8 NUMBER 2 • JUNE 2011
67
Weight management in overweight and obese patients with
type 2 diabetes mellitus
IOANNIS KYROU, SUDHESH KUMAR
Abstract
O
besity is recognised as an important risk factor for type
2 diabetes, inducing insulin resistance and pancreatic
beta-cell dysfunction. These obesity-related defects
tend to progress following weight gain and can eventually
lead to worsening hyperglycaemia over time. Thus, effective
weight management is crucial for glycaemic control in
overweight and obese patients with type 2 diabetes. Current
standard strategies for weight management in these patients
include lifestyle interventions and pharmacotherapy.
Bariatric surgery has become a promising new option for
the treatment of obese patients with type 2 diabetes and in
recent years incretin-based therapies have become available,
which exhibit favourable effects on body weight. Herein, the
efficacy of availableweight-loss interventions is assessed and
the role of newer antidiabetic agents examined, focusing on
incretin-based therapies.
Keywords:
bariatric surgery, DPP-4 inhibitors, GLP-1 analogues,
incretin-based therapies, type 2 diabetes, weight loss
Introduction
The prevalence of type 2 diabetes has risen dramatically over the
past few decades, following the continually increasing obesity
epidemic.
1,2
Recent estimates suggest that around 80–90% of
patients with type 2 diabetes are overweight or obese.
2–4
Evidence
from large-scale population studies strongly supports this close
association, identifying obesity as one of the most important
risk factors for type 2 diabetes.
5
Furthermore, accumulation of
abdominal fat is also directly associated with an increased risk
of obesity-related cardiometabolic complications,
6
and waist
circumference has been recognised as an independent risk factor
for type 2 diabetes.
7
Obesity is the cornerstone of type 2 diabetes pathophysiology,
inducing both insulin resistance and pancreatic beta-cell
dysfunction.
8
These underlying disease mechanisms usually
progress for several years before the clinical onset of type 2
diabetes, and if the excess fat mass is maintained or increases
over time, hyperglycaemia is likely to become progressively worse.
Thus, weight loss is crucial in preventing the progression of pre-
diabetes to frank type 2 diabetes.
9–11
Furthermore, in patients who
have already been diagnosed with type 2 diabetes, weight loss may
help slow the natural history of the disease and delay the need for
intensification of therapy to insulin.
10–12
However, weight reduction
in overweight and obese patients with type 2 diabetes can prove
challenging. Typically these patients lose less weight and at slower
rates than non-diabetic individuals, due to metabolic dysregulation,
potential comorbidities that restrict physical activity and a lack of
dietary adherence.
13,14
This problem is further complicated by weight
gain associated with many antidiabetic therapies, including some
oral glucose-lowering agents (i.e. sulphonylureas, glinides and
TZDs), insulin, and also, several medications prescribed for common
diabetes comorbidities (certain beta-blockers, antidepressants,
antipsychotics and neurological agents).
14,15
Importantly, it has been shown that in patients with type 2
diabetes, even a modest sustained reduction of the initial body
weight (5–10%) can significantly mitigate diabetes-related
complications by improving glycaemic control, lipid profiles and
blood pressure.
13,16,17
This review aims to provide a concise overview of the available
weight management options for overweight and obese patients
with type 2 diabetes, focusing on the efficacy of lifestyle
interventions, pharmacotherapy and bariatric surgery, as well as the
effect of incretin-based therapies on body weight. Several weight
management options have been shown to prevent the onset of type
2 diabetes in overweight individuals; however, diabetes prevention
is beyond the scope of this review and will not be covered here.
Current weight management strategies
Lifestyle interventions
Lifestyle modification should be the first step in every weight-
loss programme, aiming to improve dietary habits and increase
physical activity, and must always be included as part of diabetes
management.
18–22
Correspondence to: Prof Sudhesh Kumar
WISDEM, University Hospital Coventry and Warwickshire, Clinical Sciences
Research Institute, Warwick Medical School, University of Warwick, Coventry
CV2 2DX, UK.
Tel: +44(0) 24 765 74869
Fax: +44(0) 24 765 74871
E-mail: sudhesh.kumar@warwick.ac.uk
S Afr J Diabetes Vasc Dis
2011;
8
: 67–73.
Abbreviations and acronyms
Look AHEAD Action for Health in Diabetes
BMI
body mass index
EMA
European Medicines Agency
FDA
Food and Drug Administration
HbA
1C
glycated haemoglobin A
1c
GLP-1
glucagon-like peptide-1
GIP
glucose-dependent insulinotropic polypeptide/gastric
inhibitory polypeptide
NICE
National Institute for Health and Clinical Excellence
SU
sulphonylurea
TOGA
transoral gastroplasty
TZD
thiazolidinedione/glitazone
UKPDS
United Kingdom Prospective Diabetes Study
