If you are 40 and snoring, you may already have begun the decline into a medicalised middle age.
Australian researchers have charted the downward journey into the chronic illnesses that typically burden people from mid-life. They have mapped the first four steps beginning with snoring.
Those on the path begin to snore at the average age of 39. By about 43 they have signs of high blood pressure and by 52 they are knocking on the door of diabetes. By the time they hit 54, they have symptoms of heart disease.
The results of this study are due to be released at the Sleep DownUnder 2016 conference in Adelaide this weekend.
The question for the researchers is whether intervening early can possibly slow this sequence. If they treat the severe snoring (usually sleep apnoea), can they delay the onset of high blood pressure and so on?
For the study, specialists at The Alfred hospital in Melbourne questioned 266 snorers whose snoring was bad enough for them to seek medical help. Almost all had underlying sleep apnoea.
When the specialists investigated their other health issues, they found links to hypertension (high blood pressure), diabetes and cardiovascular disease, which are all physiologically similar and usually linked with obesity and lifestyle factors.
Of all the study participants, 43 per cent had hypertension, a quarter had diabetes and 23 per cent had some form of heart disease. Eight per cent of them had the quadrella, all four conditions.
"There appeared to be a chronological timeline from commencement of snoring to these other health problems – and that was surprising," says lead researcher and sleep physician Dr Matthew Naughton.
In those with the quadrella, the pattern was clear with snoring followed by hypertension, then diabetes and finally heart disease.
The study participants were aged around 55 and mostly male. The males generally began snoring around the age of 32, which was much earlier than the women, who started on average at 40.
Of those with the quadrella, three-quarters were male and most were in their 60s.
Despite the small sample size and although obesity and lifestyle factors need to be considered, the researchers say the sequential nature of these conditions and subsequent progression is worth investigating to test the impact of early intervention.
The treatment of sleep apnoea took a hit recently when a major trial, published in the New England Journal of Medicine, showed treating this condition in people with heart disease did not prevent further heart disease events over the next 2½ years.
Naughton says this study, and many others, suggest sleep apnoea is a risk factor for heart disease but, based upon a recent major trial, is either not a reversible one, or it may take more than 2½ years to see an effect.
He says there is good circumstantial evidence that treating sleep apnoea can lessen hypertension. An experiment in dogs has shown this is possible.
When dogs are given an operation to induce sleep apnoea, within a couple of weeks they develop high blood pressure both during the day and night. When the operation is reversed, the blood pressure drops.
This experiment shows the shift in blood pressure is not related to lifestyle factors such as poor diet and smoking.
Naughton's team is hoping to conduct a bigger study on this historic sequence to confirm its veracity.
