The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
— Tenth Amendment to the U.S. Constitution
Kidney Stones on the Rise
“Ah hah! There it is, stuck in the ureter.”
MedPage Today in May, 2012, reported a substantial increase (70%) in the prevalence of kidney stones in the U.S. over the last two decades. Stone prevalence rose from 5.2% to 8.8% of the population. Prevalence was based on the periodic National Health and Nutrition Examination Survey, which asked participants, “Have you ever had kidney stones?”
Stone prevalence began rising even earlier. Again according to the third NHANES, prevalence increased from 3.8 percent in the period 1976 to 1980 to 5.2 percent in the years 1988 to 1994.
Older studies estimated that one in 10 men and one of every 20 women will have at least one painful stone by the age of 70.
What are kidney stones make of?
Three out of four patients with kidney stones form calcium stones, most of which are composed primarily of calcium oxalate or, less often, calcium phosphate. Pure uric acid stones are less than 10 percent of all stones.
Why the increased stone prevalence? Does diet count?
Unfortunately, the article doesn’t offer any speculation as to why kidney stones are more prevalent. Kidney stones have a genetic component, but our genes have changed very little over just two decades. I wonder if diet plays a role.
UpToDate.com reviewed diet as a risk factor for kidney stones. Some quotes:
There are several dietary factors that may play an important role in many patients: fluid, calcium, oxalate, potassium, sodium, animal protein, phytate, sucrose, fructose, and vitamin C intake. Lower intake of fluid, calcium, potassium, and phytate and higher intake of sodium, animal protein, sucrose, fructose, and vitamin C are associated with an increased risk for calcium stone formation. The type of beverage may also influence the risk. The effect of calcium intake is paradoxical, with a decreased risk with increased dietary calcium and an increased or no change in risk with calcium supplements.
The combination of dietary factors may also have a significant impact upon stone risk. As an example, the Dietary Approaches to Stop Hypertension (DASH) diet is high in fruits and vegetables, moderate in low-fat dairy products, and low in animal protein. Based upon an analysis of three large cohorts, adherence to a DASH-style diet lowered the risk for kidney stones among men, older women, younger women, high body mass index (BMI) individuals, and low BMI individuals. Thus, the DASH diet is a reasonable option in the attempt to reduce the risk of stone recurrence.
Higher sucrose [table sugar] intake is associated with an increased risk of stone formation in younger and older women.
Standard advice to prevent initial and recurrent kidney stones is to avoid low urine output. Do that by drinking plenty of fluid.
Although I pay about $400 a year for access to UpToDate, they offer free public access to some of the website. Here’s the UpToDate poop sheet on kidney stones.
Extra credit: Medical conditions that predispose to kidney stones include primary hyperparathyroidism, obesity, gout, diabetes, and medullary sponge kidney.
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A Dietitian’s View of Ketogenic Diets
You get it?
Registered Dietitian Franziska Spritzler recently reviewed the concept of low-carb ketogenic diets. She thinks they are a valid approach to certain clinical situations. Among dietitians, this puts her in a small but growing minority.
I hesitate to mention this, but I will anyway. Many, if not most, dietitians too easily just go along with the standard party line on low-carb eating: it’s rarely necessary and quite possibly unhealthy. Going along is much easier than doing independent literature review and analysis. I see the same mindset among physicians.
Franziska breaks the mold.
Filed under ketogenic diet
“Doc, How Long Will I Live With My Type 1 Diabetes?”
Type 1 diabetics diagnosed in childhood and born between 1965 and 1980 have an average life expectancy of 68.8 years. That compares to a lifespan average of 53.4 years for those born between 1950 and 1964. The figures are based on Pittsburgh, PA, residents and published in a recent issue of Diabetes.
Elizabeth Hughes, one of the very first users of insulin injections, lived to be 73. She started on insulin around 1922.
Average overall life expectancy in the U.S. is 78.2 years—roughly 76 for men and 81 for women.
Don’t be too discouraged if you have diabetes: you have roughly a 50:50 chance of beating the averages, and medical advances will continue to lengthen lifespan.
Filed under Diabetes Complications
Six Weeks of Hillfit
Last January I wrote a favorable review of Chris Highcock’s Hillfit strength training program for hikers. A few months ago I actually followed the the program for six weeks, and I still like it. It’s an eye-opener.
See my prior review for details of the program. Briefly, you do four exercises (requiring no special equipment) for fifteen minutes twice a week. Who doesn’t have time for that?
Wanna arm wrestle?
I did modify the program a bit. I included high-intensity intervals on a treadmill twice weekly, right after my Hillfit exercises. Here’s the 15-minute treadmill workout: 3 minute warm-up at 5.3 mph, then one minute fast jogging at 7–8 mph, then one minute of easy jog at 5.3 mpg. Alternate fast and slow running like that for 6 cycles. So my total workout time was 30 minutes twice weekly.
Why the treadmill HIIT (high intensity interval training)? For endurance. I’m still not convinced that strength training alone is adequate for the degree of muscular and cardiopulmonary endurance I want. I’m not saying it isn’t adequate. That’s a self-experiment for another day. In 2013, I’m planning to hike Arizona’a Grand Canyon rim to rim with my son’s Boy Scout troop. That’s six or eight miles down, sleep-over, then six or eight miles back up the other side of the canyon. That takes strength and endurance.
One part of the program I wasn’t good at: Chris recommends taking about 10 seconds to complete each exercise motion. For example, if you’re doing a push-up, take 10 seconds to go down to the horizontal position, and 10 seconds to return up to starting position with arms fully extended. I forgot to do it that slowly, taking five or six seconds each way instead.
I’ve preached about the benefits of baseline and periodic fitness measurements. Here are mine, before and after six weeks of Hillfit and treadmill HIIT:
- weight: no real change (168 lb or 76.2 kg rose to 170 lb or 77.3 kg)
- body mass index: no change (23.3)
- resting heart rate and blood pressure: not done
- maximum consecutive push-ups: 30 before, 34 after
- maximum consecutive pull-ups: 7 before, 8 after
- maximum consecutive sit-ups: 30 before, 37 after
- time for one-mile walk/run: 8 minutes and 45 seconds before, down to 8 minutes and 35 seconds after
- vertical jump (highest point above ground I can jump and touch): 108.75 inches or 276 cm before, to 279.5 cm after
- waist circumference: no real change (92 cm standing/87 cm supine before, 92.5 cm standing/87.5 cm supine after)
- biceps circumference: no real change (33 cm left and 33.5 cm right before; 33 cm left and 33 cm right after)
- calf circumference: 39.5 cm left and 39 cm right, before; 38.5 cm left and 37 cm right, after (not the same child measuring me both times)
- toe touch (stand and lock knees, bend over at waist to touch toes: 7.5 inches (19 cm) above ground before, 8.5 inches (22 cm) after
If these performance numbers seem puny to you, please note that I’m 57-years-old. I’m not sure exactly where I stand among others my age, but I suspect I’m in the top half. I’m fit enough to be in the U.S. Army (I’m not in it, however). I’m sure I could do much better if I put in the time and effort. My goal right now is to achieve or maintain a reasonable level of fitness without the five hours a week of exercise recommended by so may public health authorities.
Take-Home Points
Overall, this program improved my level of fitness over six weeks, with a minimal time commitment. I credit Hillfit for the gains in push-ups, pull-ups, sit-ups, and perhaps vertical jump.
My time on the one-mile run didn’t improve much, if at all. This fits with my preconceived notion that strength training might not help me with leg muscle and cardiopulmonary endurance.
The Hillfit exercise progressions involve adding weights to a backpack (aka rucksack or knapsack) before you start the exercise. I’m already up to 80 lb (36 kg) extra weight on the modified row, and 85 lb (39 kg) on the hip extensions. That’s getting unwieldy and straining the seams of my backpack. I can’t see going much higher with those weights.
I expect I could easily maintain my current level of fitness by continuing Hillfit and HIIT treadmill work at my current levels of intensity. In only one hour per week. Not bad at all.
It’s possible I could get even stronger if I stuck to the program longer, or slowed down my movements to the recommended 10 seconds each way.
The key to muscle strength gain with Hillfit seems to be working the muscles steadily, to near-exhaustion over 90 seconds, gradually adding a higher work load as the days or weeks pass.
I’m setting Hillfit aside for now, only because I want to start a new self-experiment.
Hillfit is an excellent time-efficient strength training program for those with little resistance-training background, or for those at low to moderate levels of current fitness.
Note to self:
When doing a mile run on the treadmill, I tend to start out too fast, then burn out and have to slow down. That may be impairing my performance. Next time, start at 7 mph for a couple minutes then try to increase speed. Running a mile at 7 mph takes nine minutes. A mile at 7.5 mph takes 8 minutes. A mile at 8 mph takes 7 minutes and 30 seconds.
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Quote of the Day
A general dissolution of principles and manners will more surely overthrow the liberties of America than the whole force of the common enemy. While the people are virtuous they cannot be subdued; but when once they lose their virtue then will be ready to surrender their liberties to the first external or internal invader.
—Samuel Adams, 1779
Filed under Quote of the Day
Cinnamon for Diabetes? It May Work, But Just Barely
In a meta-analysis…
Cinnamon lowered A1C by 0.09%, versus the usual 1% with medication. [Given that] A1c reflects overall glucose trends, cinnamon doesn’t look that impressive. Even at the extreme of the confidence interval, cinnamon has, at best, 10% of the efficacy of drug treatments. At worst, it’s completely ineffective.
One tasty component of a Cinnabon cinnamon roll
See all the wonky details in a post by pharmacist Scott Gavura at Science-Based Medicine. I would only add that average changes in blood sugar and hemoglobin A1c in clinical studies don’t necessarily apply to an individual; some folks may respond much better than others.
Steve Parker, M.D.
Filed under Drugs for Diabetes, Supplements
Video of HIIT on Bicycle
A “stationary” bicycle
Gretchen Reynolds is the Phys Ed blogger at the New York Times. She posted a five-minute demonstration of high intensity interval training on a stationary bicycle. It’s narrated by Martin Gibala of McMaster University.
No mention of Tabata’s pioneering work.
-Steve
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AHA and ADA Position Paper On Non-Nutritive Sweeteners
The American Heart Association and American Diabetes Association just published a review paper on nonnutritive sweeteners, also known as low-calorie sweeteners, artificial sweeteners, noncaloric sweeteners, and intense sweeteners. I quote from the conclusion section:
At this time, there are insufficient data to determine conclusively whether the use of NNS to displace caloric sweeteners in beverages and foods reduces added sugars or carbohydrate intakes, or benefits appetite, energy balance, body weight, or cardiometabolic risk factors.
With regard to nonnutritive sweeteners and glycemic response [in diabetics], 4 randomized trials that varied from 1 to 16 weeks in duration found no significant difference between the effects of nonnutritive sweeteners and various comparisons (sucrose, starch, or placebo) on standard measures of glycemic response (i.e., plasma glucose and insulin, HbA1c, C-peptide) and, in general, did not detect clinically relevant effects.
You’re welcome to read the entire document.
-Steve
Filed under Sugar Substitutes
Diabetic Mediterranean Diet 