People in some parts of England are twice as likely to have diabetes as those in others, according to new figures.
Brent in north London has the highest rate in the country, with 10.5% of over-16s having diabetes.
This is almost double the rate in the City of London (5.5%), which has England's lowest rate despite being just three miles from Brent, according to analysis by the charity Diabetes UK.
Newham in east London also has a high rate (9.9%) as does Wolverhampton (9.6%) and Harrow in north London (9.4%).
Other hot spots include Sandwell in the West Midlands (9.4%), Leicester (9.3%), Walsall (8.8%), Blackburn with Darwen in Lancashire (8.7%), Redbridge in north London (8.7%), and Birmingham (8.7%).
The vast majority of cases are of type 2 diabetes, which is linked to unhealthy lifestyles and obesity.
Across the whole of the country, 7.4% of people aged over 16 are now thought to have diabetes and this is expected to rise to 8.4% by 2020.
Barbara Young, chief executive of Diabetes UK, said: "It is truly alarming that there is now somewhere in England where more than one in 10 of the people have diabetes and shows that we are heading at frightening speed towards a future where diabetes becomes the norm.
"Given that the increase in diabetes cases is mainly due to a sharp rise in type 2 diabetes, the only way we will finally bring the increase under control is by getting much better at preventing cases of type 2.
"A vital first step towards this is to ensure both that people realise how serious it is and also that they understand their own personal risk so that if they are at high risk they can make the simple lifestyle changes that can help prevent it.
"This is why we need to raise awareness that if people are overweight, have a large waist or are over 40, they need to get a risk assessment, as should people who have a family history of diabetes or are South Asian and over 25.
"I know that we all have busy lives and that thinking about future health can be uncomfortable, but it is only if people grasp the nettle and get their risk assessed that we can avoid a future where there are many areas where one in 10 of the population have diabetes."
In the UK, there are around 3.8 million people who have either type 1 or type 2 diabetes, with type 2 accounting for about 90% of cases.
This figure includes around 850,000 people who have type 2 diabetes but do not know it.
As many as seven million people are at high risk of developing type 2 and, if current trends continue, an estimated five million people will have diabetes by 2025, according to Diabetes UK.