Is bad sleep killing you? Tips to improve your sleep

Irregular sleep is linked to increased risk in heart attack, dementia and depression, so a routine is crucial. 

NICK HARDING FROM THE TELEGRAPH

Your mum was right when she badgered you to go to sleep at bedtime, according to the latest sleep research. In what is described as the most comprehensive study of its kind, scientists have concluded that regardless of sleep duration, failing to stick to a regular bedtime and waking time increases the risk of stroke, heart attack and heart failure by 26 per cent. It’s enough to give you nightmares.

The research involved 72,269 people and found that going to bed and waking up at different times each day was “strongly associated” with a higher risk of major adverse cardiovascular events, even if subjects regularly achieved the sweet spot of eight hours of shut eye.

Dr Kat Lederle, a sleep specialist and therapist, explains that the processes that take place during sleep are intricately timed in line with the body’s circadian rhythm: “They take place in a certain sequence. If you shift one thing, it has a knock-on effect on the others. We know for example that sleep is important for the regulation of our hormones and if that happens at the wrong time other processes are impacted and we get what we call internal misalignment.”

Repeated and persistent fluctuations in the body’s 24-hour rhythm appear to have dire consequences for health, knocking the body’s internal clock out of kilter.

Prof Guy Leschziner, a consultant neurologist at HCA Healthcare UK’s London Bridge Hospital, explains that sleep regulates vital functions in the body and that timing plays a crucial role in these.

“There are multiple functions of sleep that relate to brain and body maintenance, such as healing, development, blood pressure regulation, memory consolidation and appetite regulation,” he says. “We spend a third of our life asleep but if you’re only doing it for substantially less time, those normal mechanisms of sleep become disrupted, which has consequences to your daytime function and your health overall.”

So, what are the consequences of poor sleep?

Blood pressure

The body’s autonomous nervous system is divided into two major networks, the sympathetic and parasympathetic nervous systems, which have opposite roles. The sympathetic system carries signals that put your body’s systems on alert, using hormones such as the stress hormone cortisol. It is most active during the day. The parasympathetic nervous network carries signals that relax those daytime systems at night. If sleep is disrupted the balance between the two systems becomes unequal and can lead to higher cortisol levels. Studies show that excess cortisol can lead to elevated blood pressure.

Dr Lederle explains: “Lack of sleep means we are awake, which will then lead to an activation of that sympathetic nervous system, which then disrupts hormone regulation.”

Weight gain/obesity

Sleep also allows the body to regulate leptin, a hormone which reduces appetite, and ghrelin, which increases it. When a person sleeps, leptin levels normally rise, subduing appetite. Sleep deprivation increases ghrelin levels and at the same time lowers leptin levels, making us crave high density calorific food, which over time can lead to weight gain.

Diabetes

According to Prof Leschziner, even a single night of sleep deprivation can significantly disrupt the way that our body processes glucose, termed as our glucose tolerance or insulin resistance. Insulin regulates blood sugar levels because it moves glucose out of the bloodstream into cells where it provides an energy source. Diabetes is a chronic disease that occurs when the body doesn’t produce enough insulin or can’t use it properly, resulting in high blood sugar levels, or hyperglycaemia, which causes a range of serious health problems including cardiovascular disease and kidney damage.