How Sleep Deprivation Leads to Cardiovascular Diseases

Getting sufficient sleep is pivotal to health and wellbeing. But as many as one in three adults are not getting enough sleep [1]. Insufficient sleep can lead to several health conditions, including cardiovascular disease.

How does sleep deprivation affect your heart? 

A lack of sleep can lead to the following cardiovascular conditions:

• Hypertension. A lack of sleep can elevate our blood pressure, and even a small increase in blood pressure can, over time, increase the chances of developing heart disease [2].
• Obesity. Sleep plays a role in metabolism and hormone regulation. This means that you might find it harder to lose weight if you are sleep deprived. Also, when you are sleep deprived, you are tempted to eat higher sugar foods to try and replace the lost energy and are less likely to exercise due to general fatigue.
• Type 2 diabetes. A third of people with type 2 diabetes will be affected by a cardiovascular disease. Recent data suggests that people who sleep less than 6 hours daily have a higher risk of developing diabetes compared with those sleeping 7-8 hrs [3].
• Stress. Stress can be caused by sleep deprivation but can also be the cause of your insomnia. For example, if you are stressed about work, you might experience chronic sleeplessness, which can then increase your stress levels further. It is important to try and break this cycle and resolve the core reason for your stress.

Suggestions on improving your sleep habit:

• Practice good sleep hygiene. This means no screens before bed, no working from your bed, getting into a good nighttime routine and getting up at the same time each day.
• Consider supplements. This might be a natural remedy to help you doze off.
• Exercise. Even if you initially feel tired, exercise can help you get more sleep.
• Eat healthy food. A balanced diet containing plenty of protein and vegetables can help improve your sleep quality. You should also cut down on alcohol and caffeine consumption, as these can cause sleep problems.

Contributed by:
The Harley Street Heart & Vascular Centre
https://www.harleystreet.sg/heart/
WhatsApp +65 8031 2388

References:

1. https://www.nhlbi.nih.gov/health/sleep-deprivation
2. Hypertension, Volume 77, Number 4, https://doi.org/10.1161/HYPERTENSIONAHA.120.14479
3. JAMA Netw Open. 2024;7(3):e241147. doi:10.1001/jamanetworkopen.2024.1147

Debunking Cancer Myths

As we observe World Cancer Day this month, it’s a timely reminder of the ongoing fight against cancer, a leading cause of illness and death worldwide. In Singapore, cancer was the top cause of death from 2017 to 2021, accounting for 28.2% of all fatalities (1).

Despite advancements in medical science, several myths persist, potentially delaying diagnosis and treatment. Dispelling these misconceptions is crucial for effective cancer prevention and management. Let’s take a closer look at some common cancer myths and the facts behind them.

Common Cancer Myths and Facts

1. Myth: Cancer is a Death Sentence
   Fact: While cancer is a serious disease, it is not invariably fatal. Advancements in early detection, treatment, and supportive care have significantly improved survival rates. For instance, Five-year survival for distant stage prostate cancer improved from 28.7% during 2001–2005 to 32.3% during 2011–2016 (2).
2. Myth: Only Individuals with a Family History are at Risk
   Fact: Yes, a family history of cancer can increase your risk of developing cancer, but many people who develop cancer don’t have a family history (3).
3. Myth: Cancer is Contagious
   Fact: Cancer cannot be transmitted from person to person. However, certain viruses, such as human papillomavirus (HPV) and hepatitis B and C, can increase cancer risk and are transmissible (4).
4. Myth: Superfoods Can Prevent Cancer
   Fact: No specific food can guarantee cancer prevention. A balanced diet rich in fruits, vegetables, and whole grains, combined with a healthy lifestyle, can reduce risk but not eliminate it (5).

Regular health check-ups are vital for early cancer detection, significantly improving treatment outcomes. Adhering to national screening guidelines is essential. For instance, women aged 50–69 are advised to undergo mammograms every two years to screen for breast cancer (6).

Similarly, individuals aged 50 and above should consider annual Faecal Immunochemical Tests (FIT) for colorectal cancer screening (7).

By proactively participating in recommended screening programmes and maintaining a healthy lifestyle, you can enhance your chances of early detection and successful treatment.

References

1. Health365.sg. (2024). Cancer In Singapore – Health365. [online] Available at: https://www.health365.sg/cancer/ [Accessed 10 Jan. 2025].
2. Siegel, D.A. (2020). Prostate Cancer Incidence and Survival, by Stage and Race/Ethnicity — United States, 2001–2017. MMWR. Morbidity and Mortality Weekly Report, [online] 69. doi: https://doi.org/10.15585/mmwr.mm6941a1
3. Cancer Research UK (2018). Family history and inherited cancer genes. [online] Cancer Research UK. Available at: https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/inherited-cancer-genes-and-increased-cancer-risk/family-history-and-inherited-cancer-genes
4. Schiller, J.T. and Lowy, D.R. (2013). Virus Infection and Human Cancer: An Overview. Viruses and Human Cancer, pp.1–10. doi: https://doi.org/10.1007/978-3-642-38965-8_1
5. Holmes, S. (2006). Nutrition and the prevention of cancer. The journal of family health care, [online] 16(2), pp.43–6. Available at: https://pubmed.ncbi.nlm.nih.gov/16715752/
6. Qaseem, A., Lin, J.S., Mustafa, R.A., Horwitch, C.A., Wilt, T.J. and Clinical Guidelines Committee of the American College of Physicians*, 2019. Screening for breast cancer in average-risk women: a guidance statement from the American College of Physicians. Annals of internal medicine, 170(8), pp.547-560. doi: https://doi.org/10.7326/m18-2147
7. Recommendations on screening for colorectal cancer in primary care. (2016). Canadian Medical Association Journal, 188(5), pp.340–348. doi: https://doi.org/10.1503/cmaj.151125

The Importance of Pre-Exercise and Pre-Marathon Cardiac Screening

As cardiologists, we encourage regular moderate exercise to reduce your long term risk of heart disease.

An athlete’s sudden cardiac death is one of the tragic risks of strenuous exercise in the presence of a dormant cardiac abnormality.

Most major international sports organisations recommend a pre-exercise cardiac screening for the participants. The aim of screening is to identify these “silent” but high-risk problems that increase the risk of death due to high-intensity exercise.

In younger athletes – under 35 years – the usual causes of sudden cardiac death are due to structural abnormalities affecting the heart. These abnormalities can be genetic or acquired. They can affect the heart muscle, valves or anomalous origin of the coronary arteries. Another major subset of conditions that run a higher risk are electrical cardiac abnormalities. Cardiologists believe that the mechanism of sudden death is secondary to a malignant arrhythmia.

In older people, the most common cause of sudden cardiac death is due to coronary artery plaque rupture leading to a heart attack. High blood pressure, smoking, high LDL cholesterol, diabetes and a family history of premature coronary disease increase this risk.

The vast majority of individuals who suffered a fatal cardiac event showed no prior symptoms. Worrying clinical features include:

• Chest pains, giddiness, dizzy spells, palpitations or blackouts during exercise
• Feeling short of breath which is out of proportion to the intensity of the exercise
• Family history of a hereditary cardiac disorder or sudden cardiac death

The pre-exercise cardiac screening includes a medical history, physical examination, an ECG and echocardiogram. All the tests are safe, non-invasive, can be done at a clinic and take no longer than 1 hour to perform. Currently, genetic testing for common genetic cardiac conditions is not part of a cardiac screening.

Another pre-exercise screening test is cardiopulmonary exercise testing (CPET). This is a non-invasive simultaneous measurement of the cardiovascular and respiratory systems during exercise to assess an individual’s capacity. A CPET has many applications for evaluating a wide range of cardiac problems. The peak VO2 max achieved is a measure of someone’s maximal physiological uptake of oxygen. This means that it can act as a surrogate marker of cardiovascular fitness. The peak VO2 max can guide exercise training programs.

Pre-exercise screening has the potential to identify a high-risk subgroup of individuals. Based on the results, doctors can then tell them about their best exercise options. In the case of a high-risk patient, the screening will also provide an opportunity to prevent sudden cardiac death by implantation of an automated cardio-defibrillator.

Contributed by:
The Harley Street Heart & Vascular Centre
https://www.harleystreet.sg/heart/
WhatsApp +65 8031 2388

Recurrent Urinary Tract Infection

I get urine infection very often; do I have recurrent Urinary tract infection (rUTI)?

rUTI refers to getting at least 2 infections in six months or at least 3 infections in one year.

The episode of UTI must be confirmed with positive urine culture.

Is this common?

rUTI is one of the most common conditions affecting mainly women.

It is estimated that around 50–60% of women will develop UTIs in their lifetimes and Escherichia coli is the most common organism that causes UTI.

Is rUTI related to sex?

Yes. Sexual intercourse and the use of spermicide can be the cause of rUTI especially in young and pre-menopausal women.

What are the other causes of rUTI?

Young and pre-menopausal women	Post-menopausal and elderly women
Sexual intercourse Use of spermicide A new sexual partner A mother with a history of UTI History of UTI during childhood Blood group antigen secretory status	History of UTI before menopause Urinary incontinence Atrophic vaginitis due to oestrogen deficiency Increased post-void urine volume Blood group antigen secretory status

Adapted from European Association of Urology (EAU) guidelines

Am I genetically at risk of getting rUTI?

Yes, it is possible. The different blood groups secretor substances may influence the availability of these receptors on the urothelial cells (cells on the surface of the bladder) thereby affecting bacterial adherence and the susceptibility to UTI.

The frequencies of secretor status in different ABO blood groups are 70.1% in group A, 67.8% in group B, 67.9% in group AB, and 88.3% in group O.

Hence blood group B and AB individuals are at risk of getting recurrent UTI.

What should I expect at my first visit to a Urologist?

Your Urologist will first take a history, perform physical examination and do a series of tests to establish the diagnosis of rUTI. These may include:

• Midstream urine analysis
• Urine Culture and Sensitivity analysis of the bacteria involved
• Bedside ultrasound examination of the kidneys and bladder
• Uroflowmetry and post void residual urine

Depending on your symptoms, further tests such as CT scan or Cystoscopy might be offered by the Urologist.

The purpose of these tests is to exclude any organic causes to the recurrent nature of the UTI. These include stones, downstream obstruction such as prostate enlargement or by prolapsed organs (women) and most importantly to rule out underlying cancers that could account for the symptoms.

What is the prevention for rUTI?

• Lifestyle and behavioral modification
• Probiotics, cranberry and D mannose prevention
• Antibiotics prevention
• Immunoactive prophylaxis or oral vaccines

Prevention is better than cure!

Lifestyle and behavioral modification

• Drink plenty of fluids
• To urinate regularly
• Not holding urine for a long time . This allows bacteria to multiply within the urinary tract, resulting in UTI.
• Pass urine after sexual intercourse
• Avoid spermicidal contraceptives if possible, diaphragms and vaginal douching with shower cream, soap or lotions. This will irritate the vagina and urethra area and facilitate the entry and colonisation of bacteria. They could alter vaginal flora and cause UTI.
• To wipe from front to back, which will reduce the spread of E. coli from the perigenital area to the urethra.
• Vaginal estrogen creams or rings may also reduce the risk of UTI in postmenopausal women

Probiotics, cranberry and D mannose prevention

Taking regular probiotics, cranberry supplements and D mannose has been shown to have positive effects towards rUTIs.

Do remember not all Lactobacillus strains are effective for vaginal flora restoration and rUTI prevention.

The highest efficacy was shown with L. rhamnosus GR-1, L. reuteri B-54, L. reuteri RC-14, L. casei shirota, and L. crispatus CTV-05.

Antibiotics prevention

1. Self-start regime – If you are familiar with the symptoms and it has been proven with a urine culture before, the urologist may advise you to self-start antibiotic treatment whenever you are experiencing the start of the UTI symptoms.

2. Post sexual intercourse self-start – If the UTI happens mostly after sexual intercourse, your Urologist may advise you to self start a 3-day prophylactic course of antibiotics after sexual intercourse.

3. Long term low dose antibiotic regime – Your urologist may advise you to take a 3 to 6 month daily course of low dose antibiotics to prevent recurring UTI. This is usually advised when all conservative measurements fail.

Immunoactive prophylaxis or oral vaccines

The 2 most common used oral vaccines in the market are OM-89 and MV 140.

Several meta-analyses and systematic reviews based on Randominsed controlled trials have shown that oral immunotherapy is effective and safe method for the prevention of rUTIs compared to placebo at short-term follow up to 12months.

OM-89 or Uro-Vaxom® has been shown effective in preventing E coli rUTI in women compared to placebo. It is an oral capsule to be taken once a day for 3 months with or without subsequent booster dose.

On the other hand, MV 140 or Uromune™, a Sublingal spray to be taken twice a day for 3 months is effective in preventing 4 different types of bacteria causing rUTI ( Ecoli, Klebsiella pneumoniae, Proteus vulgaris and Enterococcus Faecalis).

These 2 oral vaccines have been recommended in European Association of Urology (EAU) in its guidelines. In Singapore, these vaccines are brought in through HSA’s Special Access Route.

Please visit your Urologist today to find out more.

Contributed by:
Dr Shirley Bang
Urologist

Advanced Urology Associates
Appointments: +65 6738 1838
Email: enquiry@urology.com.sg
https://urology.com.sg/

Why Thyroid Disease Matters to your Cardiologist

The thyroid gland regulates the body’s metabolism through the production of the hormones thyroxine (T4) and triiodothyronine (T3). While often associated with weight management and energy levels, thyroid health also has a significant impact on cardiovascular health. Thyroid function can easily be assessed with simple blood tests.

Thyroid hormones influence heart rate, cardiac output, and vascular resistance. When thyroid function is disrupted—either by hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid)—it can lead to complications that increase the risk of heart disease.

In hypothyroidism, low levels of thyroid hormones slow the heart rate and reduce cardiac output. It also raises levels of LDL cholesterol (“bad cholesterol”), which contributes to atherosclerosis, the disease process that results in coronary arteries becoming narrowed, thereby increasing the risk of heart attacks. Additionally, hypothyroidism may lead to diastolic dysfunction, where the heart has difficulty relaxing between beats.

Conversely, hyperthyroidism accelerates the heart rate and increases cardiac workload. This can result in conditions like atrial fibrillation, an irregular heartbeat that heightens the risk of blood clots and stroke. Persistent hyperthyroidism can also cause cardiomyopathy, weakening the heart muscle over time.

Recognizing the link between thyroid health and heart disease is essential for early detection and prevention. Symptoms such as fatigue, unexplained weight changes, palpitations, or swelling should prompt a discussion with your doctor. Early detection of thyroid imbalance and proper management whether through medication, lifestyle changes, or surgery, can significantly reduce cardiovascular risks. 

Contributed by
Dr Rohit Khurana
Consultant Cardiologist

Harley Street Heart and Vascular Centre
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