Tuesday, 27 January 2015

Future holidays

A bench and a doorway in the sunshine
King's Lynn, August 2014
Every so often, I spend a week over the New Year holiday period with a group of friends at a large property somewhere in the UK (although one year we were in Ireland) - I have reported on this before (three times over the lifetime of this and the previous blog). Most of the previous holidays were arranged and booked by one particular couple. This year, during a weekend I spent meeting up with some of said friends including the couple who usually make the arrangements, I nobly volunteered Lola II to arrange another of the New Year shindigs.

Somehow it has turned out that the bulk of the work so far has fallen to me instead of Lola II. This is probably only fair, since she didn't have any say in the volunteering process. So off I went, getting people to commit to joining in, finding properties to house 21 people, discovering that the level of enthusiasm meant that we needed a bigger place, collating preferences for four different properties, and at last I hope we have reached a consensus on a suitable house for us. Now my fingers are crossed that it is still available, although we do have a backup option.

That took up quite a bit of time and headspace this week, alongside the usual badminton and work. So my outstanding jobs that are far less attractive (buying holiday insurance, breakdown cover, changing utility supplier, and - worst of all - clearing moss and mud off the hall roof and gutter) have been neglected, as they are likely to continue to be neglected until I have no choice but to knuckle down. The holiday insurance will probably be first, given that the date of the holiday is set and not far off now.

And on that very subject, I took myself off to the Snowdome to put in an hour's practice, so that my first turns on Italian snow are made with some confidence. It had to be at a weekend, so I thought I'd get in early on Sunday morning hoping to start before the main rush of the day, but no such luck, it was teeming. Quite a few were in groups being taught, so they weren't getting in the way too much, but no full speed zipping down the slope. It was still worth it, even though just for an hour on a tiny slope full of beginners. I came home buzzing with excitement and anticipation for my holiday, which is as it should be.

This holiday activity inspired me to consider what other plans I might make for the coming year, and I have two or three more ideas. One slight difficulty is that the lumbering hulk of bureaucracy that is the NHS manages annual leave for its staff through an electronic interface which deals in hours - in the current year, my allocation was around 273 hours, which includes Bank Holidays. I cannot assume next year will be the same because a) you get a different allocation when you work part time compared with full time, pro rata (last year I worked 6 months on 27 hours a week, and 6 months full time) and b) I have now completed 5 years service with the NHS, which entitles me to a few more days, and I can't remember exactly how many.

So now I have to a) find out how many hours I should get next year b) find out how many of these are taken up by Bank Holidays c) convert the remaining hours to days and thus determine what I can plan for. My current thinking is that it shouldn't make any difference about the part-time vs full-time working, because although my leave hours are reduced because of part time working, I will also need to take fewer hours as annual leave. It's complicated, but it's rather delightful to be considering some lovely trips over the next 12 months at this darkest, coldest time of year.

Sunday, 18 January 2015

Nothing much to report

Pink flowers against a background of leaves
Peckover House, August 2014
Nothing much has been happening that I can blog about. There's been badminton, a trip to London, a visit from a builder to look at the damp patches on the hall walls, an attempt at running which was curtailed by a very welcome phone call from Lola II, a second visit from the builder to look at the same problem in daylight, delivering a two-part DESMOND course, more badminton, renewal of the house insurance and another run - a proper 5k Parkrun this time. It was very cold - frosty and icy - and I cobbled together an outfit that I thought would do the trick. Only my elbows were cold, so I consider that a success, given that it started to snow at one point.

Nothing else of any particular interest, although the trip to London produced all the highlights: an urban fox jumping over the fence within a couple of feet of the window we were looking through, my first ever sighting of a jay (although my second sighting came within a week in a completely different location), and participation in the Gulloebl Chinema.

Work is still good, very good. I am practising and learning and practising some more, and reflecting on my performance and receiving and giving feedback. Some patients do very well, in which case their success comes from their own efforts. Some don't do so well, in which case I try to find a different way to help them help themselves. We discuss changing long-established dietary habits. "You're not going to tell me what to do, are you?" said one patient. "That's right," I replied. "You have to decide for yourself what you're going to do, because I'm not going to be there when you're faced with a choice."

The very low carb group is thriving - at least, those who attend seem to be getting on very well. I have had a quick look over my past blog posts, and I don't think I've written about the group before. It comprises all those people who have adopted the very low carb lifestyle to help manage their diabetes, and since September we have been meeting once a month to chat about various aspects of the diet - sometimes someone brings some food they've made for people to taste, we swap recipes, and we had a speaker talking about retinal screening at one meeting. My Broccoli and Stilton Soup was very well received, as were the cheese biscuits that one of the group had made.

I have been recruiting patients to the group at a fairly slow rate, and about half of them decide after the introduction that they aren't going to carry on, but we have about ten regulars now. Everyone is weighed and has their blood pressure measured, and one of our nurses is available to consult about medication changes. They seem to enjoy the meetings and, more importantly, most are enjoying the diet, losing weight, reducing medication and are keen to continue. Only one has dropped out so far, but may return now that the festive season is over.

I participated in a small meeting to discuss our pump clinics. An increasing number of people with diabetes are using insulin pumps, and our existing provision is inadequate, leading to lengthening waiting lists for clinic appointments. There were just four of us: the main diabetes doctor who leads on pumps, our two nurses and me. At the end of the meeting I felt that things were clearer than they were at the beginning, and that is such a rare event nowadays. It looks as though we have found a way to expand the pump service, and I may have a part to play which will also increase my knowledge and skills, which is just what I like.

Thursday, 8 January 2015

What I've been reading

Image of the book cover

The Lie
by Helen Dunmore

narrated by Darren Benedict
"Cornwall, 1920: A young man stands on a headland, looking out to sea. He is back from the war, homeless and without family. Behind him lies the terror of the trenches. Daniel has survived, but will he ever be able to escape the terrible, unforeseen consequences of a lie?"
It was quite a good book, and the parts about the experience on the front line in WW1 were dramatic, gruesome, and evocative. The parts about the ex-soldier rebuilding his life but unable to shake off the traumatic reliving of the experience were also good, but his relationships with the people around him were a little sketchy. It ended as it had to, but was a little unsatisfying. Which was a shame.

Image of the book cover

The Picture of Dorian Gray
by Oscar Wilde

narrated by B. J. Harrison
"After Basil Hallward paints a beautiful young man's portrait, his subject's frivolous wish that the picture change and he remain the same comes true. Dorian Gray's picture grows aged and corrupt while he continues to appear fresh and innocent."
Another classic of English Literature narrated by my US podcaster. I suppose there just aren't enough classics of American Literature that are out of copyright, but I wish there were. To be fair, he doesn't do a bad job with this one. It's interesting to be reminded that the picture in the schoolroom (not the attic) features alongside what I suspect was Wilde's main pleasure: writing about Art, Beauty, Love and the mores of the upper and lower classes in the late 19th century.

Image of the book cover

The Siege of Krishnapur
by J. G. Farrell
"In the Spring of 1857, with India on the brink of a violent and bloody mutiny, Krishnapur is a remote town on the vast North Indian plain. The sepoys at the nearest military cantonment rise in revolt and the British prepare to fight for their lives with what weapons they can muster."
Set only about thirty years before the publication of Wilde's book above, this is a very different kettle of fish. I wasn't sure what to expect - it was a birthday present - and I'd read most of the book before deciding that it is more of a historical account than a story. If I were familiar with the history of India then I feel sure this would have provided colour and life to flesh out any dusty historical account. As it is, I now know a little bit more about the history of India.

Image of the book cover

Love in a Cold Climate
by Nancy Mitford

narrated by Patricia Hodge
"Groomed from a young age for marriage by her mother, the fearsome Lady Montdore, Polly causes a scandal when she declares her love for her uncle, the lecherous lecturer, and runs off to France."
Outstanding narration of a great book - at last, my list of 'must read classics' has come up with something worth listening to. The characters all sound like real humans, even if raised in a social milieu quite different from anything I've ever experienced. Even though there isn't much of a story as such, in the hands of this author that doesn't matter - it's still fascinating and keeps me wanting to hear the next chapter, and Patricia Hodge reads superbly. It's the second of a trilogy, and I've already lined up the first to download soon. A sparkling, wonderful book.

Image of the book cover

In Search of the Edge of Time
by John Gribbin
"The phenomena now known as black holes were described as early as 1783 and dismissed as idle speculation - invisible stars sounded just too implausible to be taken seriously. It was only with the development of radio astronomy, relativity theory and mathematical models of warped spacetime that their true significance became clear. "
As is usual in a book such as this, despite the clear writing, I feel very clever at understanding it up to about halfway, and then wallow about, hoping something will come into focus by the end. It usually doesn't. But I liked the first half, and even though I didn't really grasp the full impact of the argument, it says that time travel is possible, although seemingly not practicable. It was published in 1992 which is a long time ago in particle physics, but again I don't have the knowledge to determine what has been confirmed, ruled out or succeeded by more modern theory. The statement I liked the best was that our Universe might actually be located inside a black hole.

Thursday, 1 January 2015

SGLT2 inhibition

Red dawn sky over frosty bowling greens and clubhouse
Bowling greens at dawn, December 2014
All around are signs that a new year has started - empty roads, silent stations, Mary Poppins on TV and a host of New Year blog posts. I've been sitting on this post for a while, and as I don't have much to say about 2014 or the New Year, you can have this as my first gift of 2015.

The Diabetes Education Club meeting I attended recently featured an eminent speaker on SGLT2 inhibition in the management of high blood glucose. This is a relatively new treatment, although he described its origins in the 1800's when, following the isolation of salicylic acid from willow bark, people were mucking about with all sorts of tree bark to find something similarly therapeutic. A substance was found in apple bark, but all it seemed to do was produce glucose in the urine (glucosuria). This didn't seem useful at the time and it was even thought to cause diabetes (a symptom of which is glucosuria), so it was shelved.

More than a century later, the reality was understood - this substance inhibits the action of sodium-glucose co-transporter (SGLT) molecules which carry sodium and glucose across a cell membrane. In the gut, SGLTs enable the absorption of sodium and glucose from food into the body. In the kidney, they transport sodium and glucose from filtered blood back into the circulatory blood, and prevent glucose from being excreted in the urine.

There are two types, imaginatively named SGLT1 and SGLT2. SGLT1 works mostly in the gut but is found in the kidney as well, and SGLT2 is mostly found in the kidney. SGLT1 is a high affinity, low capacity transporter, so it catches glucose very effectively but works quite slowly. SGLT2 is a low affinity, high capacity transporter, so it lets a lot of glucose cruise on past but works very quickly. You can imagine that SGLT1 is good for low glucose concentrations, while SGLT2 works best with high glucose concentrations.

One of the functions of the kidneys is to filter the blood and get rid of waste products in the urine. Glucose in the blood passes through the kidneys and is normally totally reabsorbed back into the body; glucose is not normally found in the urine of a healthy individual. When blood glucose concentration is higher than normal, the kidneys still do a pretty good job and can cope with nearly double the usual blood glucose concentration, but eventually their capacity is exceeded and glucose is excreted in the urine.

The original apple bark extract (phlorizin) did not differentiate between the two types of SGLT. The phlorizin molecule sticks to the SGLT transporter molecules in the kidney and gut in place of glucose, and blocks the transport of glucose. The effect in the kidney results in glucosuria, and in the gut it leads to impaired absorption of glucose, with the remaining glucose fermenting in the lower intestine and causing pretty nasty side effects. Phlorizin was also too easily digested to be an effective oral treatment, so modifications were made to the molecule to inhibit digestion and to make it more selective for the SGLT2 transporter. This has resulted in the new SGLT2 inhibitor family of 'flozins', including dapagliflozin, canagliflozin and empagliflozin which are licensed in the EU (and some others are available in other parts of the world).

We burn about 250g of glucose per day, half of which is used by the brain. Some of this glucose will come from our diet, and the rest will be synthesized internally. About 180g of blood glucose a day passes through the kidney in a healthy person, and more if the blood glucose concentration is raised. Inhibiting the action of the SGLT2 transporters eliminates more than 50g of glucose per day, thus lowering the remaining blood glucose level. Although not its licensed purpose, this obviously eliminates more than 200 calories a day too, and so this treatment, unlike many diabetes treatments, has the potential to contribute to weight loss as well.

One of the disadvantages of many diabetes treatments is the risk of low blood glucose or hypoglycaemia. SGLT2 inhibition only works if blood glucose is high, because of its low affinity for glucose. If blood glucose is low it simply doesn't work very well, so there is little risk of a hypo. It also uses a different approach compared with all the other types of diabetes treatments, so can theoretically be combined with any of them, although licensing for UK prescription depends on having results of specific trials with each. Another factor in favour of the SGLT2 inhibiting treatment is that if the drug is either not effective or not acceptable (i.e. the patient doesn't take it) there will be no glucosuria, in which case it can be stopped without further ado.

Of course there are disadvantages. If kidney function is not good enough to filter blood effectively then this drug will not be effective. And glucose in the urine is all very well as long as bacteria and fungi don't take advantage. The doctors report that female patients are generally pragmatic about identifying and treating urinary tract infections and thrush, but they say that the male patients tend to either overreact or ignore the problem until it has got so bad it can't be overlooked any longer.

There doesn't appear to have been any direct comparison of treatment with SGLT2 inhibitors compared with dietary approaches to lowering blood glucose. The trials that have been done are comparing treatments with placebo, where sustained weight loss has been about 2kg and reduction in blood glucose has been demonstrated either with improved HbA1c results or a reduction in insulin dosage or a slowing of diabetes progression compared with a control group. There is also a small diuretic effect, which probably accounts for a slight improvement in blood pressure as well.

Because the inhibition affects sodium (the 'S' in SGLT) as well as glucose there are possible negative effects on sodium balance in the body. Recently, I attended a doctors' meeting (by accident) where the doctors raised this issue, but also questioned the size of the effect on HbA1c given the small amount of glucose that is actually eliminated in this way, and wondered what else might be going on. I am not entirely convinced either by the claims made or by the scepticism of the doctors. All I know is that it is another possible treatment for raised blood glucose, and I'll wait and see how it all turns out. That's the beauty of the Dietitian's job - all observation, very little responsibility, mostly trial and error.

Reference: Tahrani, Abd A et al. 'SGLT inhibitors in management of diabetes'. The Lancet Diabetes & Endocrinology, 1:2, p140-151. http://dx.doi.org/10.1016/S2213-8587(13)70050-0
Related Posts Plugin for WordPress, Blogger...