July Group Meeting - Circadian Cycles and Clock Genes

Our group welcomed Dr Alan Jackson, who is a diabetologist at Broomfield Hospital, on Tuesday 17 July 2018.  Dr Jackson gave a talk to around 25 members on ‘Clock Genes and Circadian Cycles’.

The study of circadian rhythms is called chronobiology.  Circadian rhythms are physical, mental, and behavioural changes that follow a daily cycle. The rhythms respond primarily to light and darkness. Sleeping at night and being awake during the day is an example of a light-related circadian rhythm. Circadian rhythms are found in most living things, including animals, plants, and many tiny microbes. 

When we travel abroad each clock gene within our body adjusts itself to our new environment. If a human emigrates to the other side of the world the clock genes only take a few weeks to adjust to the new environment. The circadian cycle also adjusts our body to the time of year that we are in.  This provides some explanation as to why humans put weight on in the winter months and explains why some people suffer seasonal affected disorder in winter and in summer.  People who work shift patterns upset their circadian cycle and are 1.5 to 3 times more likely to develop cardiovascular disease and develop type 2 diabetes.  Dr Jackson spoke at length on this topic.

Our clock genes prepare our body for the new day.  This process sees a rise in our blood glucose levels, which enable us to get up and face the new day.  The rise in blood sugar is best seen by those who have type one diabetes.  Those with type one diabetes often wake up with a high sugar level.  The rise in early morning blood sugar in those with type one diabetes is known as the dawn phenomenon.   Those people that are on an insulin pump and those that are able to accurately predict the rise in sugar levels are able to counteract it by adjusting their insulin doses. Those on other insulin regimes have to adjust their breakfast time injections to take account of the rise in blood sugar.

Scientists and doctors are investigating further on what makes our biological clocks tick, with the hopes that new treatments will be found for sleep disorders, obesity, mental health disorders, jet lag and many other disorders.  It is also hoped that understanding our biological clocks will help improve ways for individuals to adjust to night-time shift work.