Department of Circadian & Sleep Health
The Department of Circadian & Sleep Health focuses on understanding how the body’s internal clock and sleep patterns influence diabetes and overall metabolic health. It also addresses how correcting sleep-related disorders can significantly improve long-term health outcomes.
Many individuals experience fatigue, poor concentration, snoring, disturbed sleep, or difficulty controlling blood sugar—often without realising that the underlying cause may be a sleep or circadian rhythm disorder.
This department is dedicated to identifying and managing these conditions through evidence-based sleep medicine and circadian health care.
Why Circadian & Sleep Health Matters
Modern lifestyles have significantly disrupted natural sleep patterns. Factors such as late-night screen exposure, irregular meal timings, stress, shift work, poor sleep habits, and inadequate sunlight exposure can disturb the body’s internal biological clock—known as the circadian rhythm.
Disruption of this rhythm can lead to:
- Poor diabetes control
- Weight gain and obesity
- Insulin resistance
- High blood pressure
- Fatigue and low energy
- Mood disturbances and brain fog
- Reduced concentration and productivity
- Hormonal imbalance
- Increased cardiovascular risk
Research has consistently shown strong links between poor sleep and conditions such as type 2 diabetes, obesity, fatty liver disease, hypertension, and metabolic syndrome.
What is Circadian Rhythm?
The circadian rhythm is the body’s natural 24-hour internal clock that regulates essential physiological functions, including:
- Sleep–wake cycles
- Hormone release
- Blood sugar regulation
- Appetite and digestion
- Body temperature
- Energy levels
- Cell repair and recovery
This system is primarily influenced by light exposure and coordinates the functioning of various organs. When aligned, the body performs optimally; when disrupted, it negatively impacts both physical and mental health.
Signs of Sleep or Circadian Disorders
You may benefit from evaluation if you experience:
- Loud or habitual snoring
- Persistent morning fatigue despite adequate sleep
- Excessive daytime sleepiness
- Difficulty falling or staying asleep
- Frequent nighttime awakenings
- Morning headaches
- Nocturnal urination
- Difficulty concentrating
- Irritability or mood changes
- Brain fog and reduced productivity
- Poor blood sugar control despite treatment
- Unintended sleep episodes during inactivity
- Observed pauses in breathing during sleep
- Shift work–related sleep disturbances
- Jet lag or irregular sleep patterns
Snoring and Sleep Apnoea
While occasional snoring may be harmless, persistent loud snoring can indicate Obstructive Sleep Apnoea (OSA).
OSA occurs when the airway repeatedly collapses during sleep, causing interruptions in breathing and reduced oxygen levels.
Common symptoms include:
- Loud snoring
- Choking or gasping during sleep
- Morning fatigue
- Dry mouth on waking
- Poor concentration
- Memory issues
- Resistant diabetes or hypertension
Many individuals with diabetes and obesity may have undiagnosed sleep apnoea. Timely diagnosis and treatment can significantly improve:
- Sleep quality
- Energy levels
- Blood sugar control
- Blood pressure
- Cardiovascular health
- Overall quality of life
Diabetes and Sleep: The Hidden Link
Sleep plays a critical role in glucose metabolism. Poor sleep can:
- Increase insulin resistance
- Raise fasting blood glucose levels
- Increase appetite and cravings
- Elevate stress hormones such as cortisol
- Promote weight gain
- Worsen HbA1c levels
Even short-term sleep deprivation can impair insulin sensitivity. Individuals with untreated sleep disorders often struggle to achieve optimal glycaemic control despite medication and dietary management.
Services Offered
Sleep & Circadian Health Consultation
Comprehensive evaluation of sleep patterns, lifestyle factors, circadian rhythm, and metabolic health.
Sleep Disorder Evaluation
- Obstructive Sleep Apnoea (OSA)
- Insomnia
- Circadian rhythm disorders
- Shift work sleep disorder
- Excessive daytime sleepiness
- Snoring-related conditions
Sleep Apnoea Screening
Clinical evaluation and recommendation for diagnostic sleep studies when indicated.
Circadian Health Assessment
Assessment of how light exposure, meal timing, exercise, and lifestyle influence metabolic health.
Lifestyle & Behavioural Sleep Therapy
- Sleep hygiene optimisation
- Structured bedtime routines
- Light exposure management
- Meal timing strategies
- Stress management techniques
- Screen exposure reduction
Diabetes & Sleep Optimisation
Integrated care for managing metabolic disturbances associated with sleep disorders.
ENT & Airway Evaluation
Assessment of structural causes of snoring and sleep-disordered breathing.
CPAP Therapy Guidance
Support and follow-up for patients requiring CPAP treatment for sleep apnoea.
Who Should Consult?
- Individuals with habitual snoring
- Persistent fatigue despite adequate sleep
- Diabetes with poor glycaemic control
- Night shift workers
- Chronic fatigue or daytime sleepiness
- Obesity or metabolic syndrome
- Resistant hypertension
- Insomnia or irregular sleep schedules
- Frequent jet lag
- Observed breathing pauses during sleep
Frequently Asked Questions
Can poor sleep affect blood sugar levels?
Yes. Poor sleep reduces insulin sensitivity and worsens glucose control.
Why do I feel tired despite sleeping?
This may indicate poor sleep quality due to conditions like sleep apnoea or circadian disruption.
Is snoring dangerous?
Persistent loud snoring may indicate sleep apnoea, which increases the risk of cardiovascular and metabolic diseases.
What is a sleep study?
A diagnostic test that monitors breathing, oxygen levels, heart rate, and brain activity during sleep.
Can treating sleep disorders improve diabetes?
Yes. Treatment can improve insulin sensitivity, HbA1c levels, and overall metabolic health.
How much sleep is required?
Most adults need 7–9 hours of quality sleep per night.
Does screen time affect sleep?
Yes. Blue light suppresses melatonin and delays sleep onset.
Does shift work affect health?
Yes. It disrupts circadian rhythm and increases the risk of metabolic and cardiovascular conditions.
Simple Ways to Improve Sleep Health
- Maintain a consistent sleep schedule
- Get early morning sunlight exposure
- Limit screen time before bed
- Avoid heavy meals late at night
- Exercise regularly
- Reduce evening caffeine intake
- Create a dark, quiet sleep environment
- Seek medical advice for persistent symptoms
Dr. Mahalakshmi Rangabashyam Shetty is a Consultant in Circadian & Sleep Health at Dr. Mohan’s Diabetes Specialities Centre. She is an experienced ENT and Head & Neck specialist with international expertise in sleep medicine, circadian disorders, otology, and thyroid and parathyroid surgery.
She has trained at leading institutions including Singapore General Hospital, National Cancer Centre Singapore, and SingHealth Duke-NUS Head & Neck Centre, with over a decade of clinical experience.
Her clinical focus includes sleep disorders, circadian rhythm health, snoring, obstructive sleep apnoea, and integrated approaches to improving quality of life. She is actively involved in research, education, and quality improvement initiatives, with multiple international publications to her credit.