Type 2 diabetes in adults
History and exam
Key diagnostic factors
common
presence of risk factors
Key risk factors include older age; overweight/obesity; certain ethnic groups (including black, South Asian, or Hispanic ancestry); family history of type 2 diabetes; history of gestational diabetes; presence of non-diabetic hyperglycaemia; polycystic ovary syndrome; hypertension; dyslipidaemia; or known cardiovascular disease.[27][34]
asymptomatic
It is very common for type 2 diabetes to be asymptomatic and detected on screening. Symptoms, when present, may indicate more overt hyperglycaemia.
uncommon
polydipsia
Usually in patients with fasting plasma glucose >16.6 mmol/L (>300 mg/dL) and/or HbA1c >95 mmol/mol (>11%).
polyuria
Usually in patients with fasting plasma glucose >16.6 mmol/L (>300 mg/dL) and/or HbA1c >95 mmol/mol (>11%). As polyuria occurs when there is considerable hyperglycaemia, it is rarely seen in people with type 2 diabetes (and is a more common presentation in people with type 1 diabetes).
Other diagnostic factors
common
candidal infections
Most commonly vaginal, penile, or in skin folds.
skin infections
Cellulitis or abscesses.
urinary tract infections
Cystitis or pyelonephritis.
fatigue
Increased fatigability may be an early warning sign of progressive cardiovascular disease; clinicians should have a low threshold for cardiac evaluation.
blurred vision
Due to elevated glucose.
uncommon
polyphagia
Usually in patients with fasting plasma glucose >16.6 mmol/L (>300 mg/dL) and/or HbA1c >95 mmol/mol (>11%).
unintentional weight loss
If marked hyperglycaemia is present.
paraesthesias
May occur in the extremities as a result of neuropathy in those with prolonged undiagnosed diabetes.
acanthosis nigricans
A velvety, light brown-to-black marking, usually on the neck, under the arms, or in the groin. Can occur at any age. Most often associated with obesity. [Figure caption and citation for the preceding image starts]: Acanthosis nigricans involving the axillaFrom the collection of Melvin Chiu, MD; used with permission [Citation ends].
Risk factors
strong
older age
Older people are at increased risk. However, the incidence of type 2 diabetes in children and adolescents is increasing.[26]
overweight/obesity
Appears to be the precipitating factor leading to clinical expression of type 2 diabetes.[27][28] Compared to people without obesity, those with obesity are almost six times more likely to develop type 2 diabetes.[29] The mean body mass index (BMI) at the time of diagnosis of diabetes in several studies is around 31 kg/m², and there is a graded increase in risk of diabetes with increasing BMI.[30] Clinical trials have shown that weight loss is associated with delayed or decreased onset of diabetes in high-risk adults.[31]
gestational diabetes
The reported incidence of type 2 diabetes after gestational diabetes varies widely. A systematic review and meta-analysis of 170,000 women estimated the risk of developing type 2 diabetes after experiencing gestational diabetes was 20% at 10 years post-delivery, increasing linearly over time to 58% at 50 years post-delivery.[32] Further, a large population-based cohort study concluded that gestational glucose intolerance, including conditions not meeting gestational diabetes criteria, confers a high risk of type 2 diabetes in young adulthood.[33]
non-diabetic hyperglycaemia
family history of type 2 diabetes
Although the specific genetic profile that confers risk has yet to be fully elucidated, epidemiological observations leave little doubt of a substantial genetic component.[19]
non-white ancestry
Prevalence of diabetes varies by ethnic group. In the UK, type 2 diabetes is more common in people of African, African-Caribbean, and South Asian family origin.[36] South Asian and East Asian people are at increased risk of developing type 2 diabetes, probably due to an interplay of diet, lifestyle, and genetic factors.[37][38][39][40] Different prevalence rates have been observed for white Americans, Hispanic Americans, and African-Americans, with people of African, Hispanic, or American-Indian ancestry at higher risk of diabetes compared with white people.[41][42]
polycystic ovary syndrome
hypertension
dyslipidaemia
Especially with low levels of high-density lipoprotein (HDL) and/or high levels of triglycerides: periodic diabetes screening is recommended due to the high prevalence of diabetes in people with dyslipidaemia.[34] Statins are associated with a small increased risk of new-onset diabetes, which is higher in people with other risk factors for diabetes, and in association with high-intensity statins and older age.[18]
cardiovascular disease
stress
Stress provokes release of hormones that elevate glucose, and there is some evidence that life stress may predispose to onset of type 2 diabetes.[43]
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