Is nicotine gum making me sensitive to the cold?

Q MY HANDS, feet and nose get very cold — my hands can go white with cold, even in the summer! I have Hashimoto’s thyroiditis and for years I assumed I got cold because of that. But my kidney function tests also show a decline.

I gave up smoking in 2005 and have been addicted to nicotine gum and lozenges ever since — could that be to blame? Name and address supplied.

A Many people use nicotine therapy, and while that’s a good thing (as it helps you quit smoking), we shouldn’t ignore possible complications.

First, though, let’s start with your Hashimoto’s thyroiditis, which is the most common cause of an underactive thyroid. It occurs as a result of the body’s antibodies attacking the gland.

One symptom is feeling colder than usual, as the thyroid makes hormones that control our metabolism, which maintains body temperature.

This causes a greater sensitivity to the cold, but you ask if other factors are involved in your case.

and it may well be that the nicotine therapy is contributing to this by causing restriction of blood vessels in the fingers, toes and nose. But might the nicotine gum and lozenges also be affecting your kidney function?

In your longer letter you say your eGFR, a measurement of kidney function based on a blood test and other factors such as age and height, was 60 — i.e. normal — two years ago; it’s now 55, which is outside the normal range.

While nicotine has been shown to accelerate the onset of kidney disease in cigarette smokers, there are no studies on long-term use of nicotine replacement therapy.

However, studies on vape users show that the nicotine exposure increases levels of creatinine, a chemical that healthy kidneys should filter out of the blood.

So it could be that the nicotine may be simply raising your creatinine levels (and lowering your eGFR), not directly harming your kidneys.

The only way you will find out if nicotine is the culprit is to stop taking it. I’d suggest cutting back by microscopic degrees each week so that by six to 12 months from now you are no longer dependent — and by then your eGFR might be back in the normal range.

In the interim, tell your GP about your nicotine intake and request a referral to a kidney specialist for additional tests as a precautionary measure.

Q I HAVE had recurrent urinary tract infections since my first Covid jab. When I finish a course of antibiotics, the infection returns in days. Why can’t I get rid of them? I am 81. Terry Payne, by email.

A I THINK your Covid jab is a red herring here — I’m afraid urinary tract infections are not uncommon in older men.

They often occur as a result of residual urine — the urine left in the bladder after emptying.

The amount left behind increases with age: in a man aged 30, it may be less than a teaspoonful, but in a man of 80, it could be half a teacupful or more.

That’s because the prostate, a walnut-sized gland that surrounds the urethra (the tube that empties urine from the bladder) becomes larger with age. This distorts the shape of the bladder so that when it’s emptied, more urine remains in it. Bugs can flourish in this residual urine, causing an infection in the urinary tract.

It is paramount that when you next develop an infection, your GP sends a fresh urine sample to a lab to identify which antibiotics are most suitable for treating it.

Options include nitrofurantoin, an antibiotic of the 1950s that has come back into favour due to the emergence of resistance to more commonly chosen antibiotics, such as cefalexin.

When the right treatment is identified, it’s also vital that a long enough course is prescribed to ensure the infection is properly cleared. This will help reduce the risk of recurrence.

However, recurrent infections are common, and many specialists opt for what is called low- dose prophylaxis — when a small dose of an antibiotic is given daily for three to six months to try to prevent recurrent infections.

Sometimes patients are prescribed methenamine, an antiseptic. However, this won’t eradicate an established infection, so should only be given to prevent a new infection developing, once the initial infection has cleared.

The way forward is obvious — a proper investigation is needed to find out exactly which bug is causing this infection, and the right antibiotic to treat it.