Background: Obesity frequently co-exists with type 2 diabetes mellitus (T2DM), leading to the socalled
“diabesity epidemic”. The metabolic syndrome (MetS), a cluster of central obesity, hypertension, dysglycemia,
insulin resistance and/or atherogenic dyslipidemia, as well as non-alcoholic fatty liver disease (NAFLD), a
hepatic manifestation of MetS, has been associated with increased cardiovascular disease (CVD), T2DM and
chronic kidney disease (CKD) incidence. However, the association between obesity, MetS (including NAFLD)
and diabetic microvascular complications is less evident.
Methods: The present narrative review discusses the associations of obesity, MetS and NAFLD with diabetic
kidney disease (DKD), diabetic retinopathy (DR) and diabetic peripheral neuropathy (DPN) as well as cardiac
autonomic neuropathy (CAN). The available data on the effects of lifestyle measures and bariatric surgery on
these diabetic complications are also briefly discussed.
Results: Overall, both obesity and MetS have been related to DKD, DR and DPN, although conflicting results
exist. Links between NAFLD and diabetic microvascular complications have also been reported but data are still
limited. Lifestyle intervention and bariatric surgery may prevent the development and/or progression of these
microvascular complications but more evidence is needed.
Conclusion: Clinicians should be aware of the frequent co-existence of MetS and/or NAFLD in T2DM patients
to prevent or treat these metabolic disorders, thus potentially minimizing the risk for both CVD and diabetic microvascular