I've talked to some people who feel browbeaten by their doctors. They lower blood sugar levels by changing diet and lifestyle, but don't get the response they expect. Lower blood sugar reduces blood pressure and endothelial damage in the circulatory system, I thought. So lower blood sugar should reduce the risk of heart attacks, I believed.
Their doctor may then turn their attention to cholesterol levels and berate the patient for 'very high levels'. If the patient takes the trouble to note down the numbers to check against NHS guidelines, they may find most numbers within the normal range, but triglycerides are a little higher. 'One swallow doesn't make a Summer' and it's not great scientific practice to take action based on a single reading for trigs (much the same as writing a prescription based on one blood pressure reading.) You need to know if it's a one-off event based on some temporary trigger or a general trend.
Back to the blood sugar.
I'm a fan of Jenny Ruhl and her easy to read guidelines on diabetes and optimum blood glucose levels.
She helped solved the mystery of these doctors' reactions:
It turns out that some doctors have come to believe a good study that reached some poor conclusions based on shoddy analysis of data. In short: the research took 2 groups of people with type 2 diabetes - one lot had no intervention and the other took steps to reduce their blood sugar levels. Some of the intervention group had heart attacks and died (more than in the non-intervention group). The conclusion reached was that lowering blood sugar levels was DANGEROUS.
Another look at the data showed that some of the intervention group cheated and DID NOT lower their blood sugar levels. Those that did had no heart attacks and became healthier.
Always view tabloid headline reports of medical research with scepticism. It might also be an idea to treat doctors' negative statements about sensible diet and lifestyle changes with some detachment. They may not have read the original research or treated it with the critical rigour it deserves.
It's your health and life.