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Chapter 1 Summary

z Type 2 diabetes mellitus (T2DM) is a chronic, progressive disease, char-
acterised by hyperglycaemia. Insulin resistance (i.e., a reduced cellular
response to the hormone) and impaired pancreatic β-cell function are the
chief pathogenetic mechanisms.
z Simple blood tests allow for the diagnosis of T2DM as well as prediabetes,
which is a condition of milder dysglycaemia at high risk of progressing to
overt T2DM.

z The criteria for the diagnosis of diabetes are as follows:
◦ Fasting plasma glucose (FPG): ≥126 mg/dl (7.0 mmol/l)
◦ Post-prandial glucose (PPG): ≥200 mg/dl (11.1 mmol/l)
◦ HbA ≥6.5%
1c
◦ Random plasma glucose: ≥200 mg/dl (11.1 mmol/l)
z Insulin has a number of key functions, including promoting the uptake of
glucose by cells throughout the body.
z In essence, the pathophysiological mechanisms involved in the develop-
ment of T2DM are the deterioration of β-cell function accompanied by a
reduced incretin effect, an over-activity of α-cells resulting in hyper-
glucagonaemia, and insulin resistance.
z The β-cells of the pancreas do not respond to rising glucose levels appro-
priately, which results in a relative lack of insulin contributing to chronic
hyperglycaemia.
◦ Many β-cell ‘aggressors’ have been identified, such as elevated glucose
and free fatty acid levels, all of which lead to β-cell damage and apop-
tosis.
z Every ten seconds, two people develop diabetes
◦ Globally, it is estimated that 285 million people have this disease (just over
6% of the global population) and by 2030, there are projected to be more
than 430 million people with this disease.

z Diabetes is the fourth leading cause of death.
◦ Every year it kills nearly four million people, almost half of whom are less
than 70 years old.
z The typical patient with new-onset T2DM has had the disease for at least
4–7 years before it is diagnosed. By the time they are diagnosed, a con-
siderable proportion of people have already started to develop diabetes-
associated complications.
z The total cost of diabetes in the US in 2007 was $174 billion.
z In the UK Diabetes accounts for approximately a tenth of the NHS’ budget
each year, a total exceeding £9 billion.
z Genetics are of fundamental importance in the emergence and the pro-
gression of T2DM and many candidate genes have been identified that
increase the risk of developing T2DM.

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