The rate of diabetes in men from Birmingham is twice as high as the UK average, according to research revealed at Diabetes UK's Annual Professional Conference in Glasgow.
The new statistics show that 14.7% (6,668) of men over the age of 40 have diabetes in Birmingham, compared to the national average of 5.8% (746,500).
Dr Felix Burden, Community Diabetologist at Heart of Birmingham Teaching Primary Care Trust, said: "The high proportion of people with type 2 diabetes in Birmingham is partly due to the current obesity crisis, its high black and South Asian population and high levels of deprivation.
"Diabetes is contributing to high rates of cardiovascular disease in inner city areas and we need to urgently find all the people with diabetes who do not know they have it. Testing should be offered to all men over the age of 40, regardless of whether they have any risk factors, so that the condition can be diagnosed earlier."
The researchers worked with 64 GP practices in Birmingham and discovered a further 3,454 men who could also potentially have type 2 diabetes and not know it.
"The high rate of diabetes is shocking," said Douglas Smallwood, Chief Executive of Diabetes UK.
"Diabetes can lead to life-threatening conditions such as stroke, heart and kidney disease. However, good diabetes control including regular physical activity and a healthy diet can cut the risk of complications and help prevent or delay the onset of type 2 diabetes."