Sea Levels 81,000 Years Ago

February 28, 2010

Climate scientists have used sea levels past and present to help predict those of the future. Temperature affects land ice; increased land ice will lower sea levels while the melting of this ice will raise these levels. Thus increased sea levels (secondary to ice melting) reflect a warmer global temperature. The scientific debate about what is actually happening to our climate has become super heated by politics, much of the warmth coming from scientists themselves.

To know the direction towards which the earth’s temperature is headed we have to know what it was in the past. Let’s pick 81,000 years ago. I picked this time for reasons that will be obvious as we progress. The temperature in the past is fixed and immutable though our ability to read it is always subject to amendment. To say as some do that there’s a consensus about climate change that is not debatable is to have no understanding whatsoever about how science works. Any consensus can be upended by new data or a new insight into existing data. Scientific disputes are not resolvable by a vote, their resolution depends on facts. Scientists are human, worse I can say about no man, thus they frequently get carried away with their beliefs and depart from scientific rigor just like anyone else.

Back to 81,000 years ago. According to commonplace wisdom, the earth should have been cooler then, it was well into the last glacial period, and the sea level supposedly 15 to 20 meters below today’s level. A paper in the February 12, 2010 issue of Science by geoscientists Dorale, et al challenges this view. “A speleothem that has been intermittently submerged in a cave on the island of Mallorca was dated to show that, historically, sea level was more than a meter above its present height. This data implies that temperatures were as high as or higher than now, even though the concentration of CO2 in the atmosphere was much lower.” Quotation from Science page 757.

An accompanying perspective piece by geologist R Lawrence Edwards from the University of Minnesota shows that estimating what the climate was 81,000 years ago is not a simple issue. “Dorale et al. provide evidence for high sea level at ~81,000 years ago, in the middle of the most recent 100,000-year cycle. This result challenges the observational basis for much of the discussion over recent decades… Dorale et al. dated layers of the mineral calcite, which were deposited like bathtub rings from pools of water in Mallorca caves, in the western Mediterranean. Because the pools are connected to the sea through underground passages, the layers record sea level at the time they formed. Using this approach, Dorale et al. inferred sea levels similar to modern values ~81,000 years ago. They estimated maximum rates of sea level rise of ~2 m per century. This rate is high, but not unprecedented in the geologic record. It exceeds by several times those predicted for the next century… A number of previous studies have estimated sea level ~81,000 years ago. Some of these estimates appear to agree with Dorale et al.’s findings, whereas others appear to disagree… Regardless of the ultimate verdict on sea level ~81,000 years ago, Dorale et al’s findings will stimulate ideas, discussion, and new studies of ice age history and causes.”

Note the conclusion by Edwards that new studies are needed. In assessing the current debate about climate change several questions must be answered as best we can. If the planet is warming is it doing so at historically unprecedented rates? Do we know why the change is occurring? If so, can we do anything about it? If we can, is the result worth the cost? The answers to all these questions are still uncertain.

The lay press and our politicians have failed miserably in informing the public of the facts and uncertainties of climate change. The subject is difficult and not close to being definitively settled.  People who are skeptical of man made global warning have been vilified. They have even been compared to holocaust deniers. Scientific disagreements are not resolved by ad hominem attacks.  Likening global warming skeptics to holocaust deniers is itself so anti-scientific as to be like holocaust denial. The proper response to this subject is to gather more information before changing the entire world’s economy in an effort to save the planet – a task that may prove unnecessary or impossible.

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Forgotten Miracle

February 26, 2010


Glory does not always blaze; sometimes it goes dark. The 1960 USA hockey team is an example forgotten greatness.

Olympic hockey is now one of the winter games premiere events. Professional players from the NHL form the core of the strong teams’ rosters. This year’s Winter Olympics mark the 30th anniversary of the USA’s improbable hockey gold medal at the Lake Placid games. Most everyone is familiar with that team’s underdog win. And if somehow you  don’t know the story NBC’s commentators will remind you of it every time hockey is mentioned on their broadcasts.

But this year is also the 50th anniversary of an equally improbable USA hockey gold medal. The 1960 US team was not given a chance of beating either Canada or the USSR at the Squaw Valley games. Canada and the USSR were the two powerhouses of international “amateur” hockey. Czechoslovakia and Sweden were also ranked above the American team. Yet the US beat all four winning the gold medal with a 7-0 record.

To commemorate the 50th anniversary of one of the greatest achievements is US sports history Golden Puck Pictures has released a 65 minute documentary – Forgotten Miracle. The video, produced with the cooperation of USA Hockey and the US Olympic Committee, is a compelling account of how 17 American amateurs (remember the root of the word is lover) pulled off one of the most thrilling series of upsets since George Washington took command of an army of New Englanders.

In 1960 hockey was a man’s game – a real man’s game. No helmets, no masks, no teeth; the 1960 Olympics were played outdoors. Forgotten Miracle tells the story with half century old film and TV clips and with interviews of the surviving players and their coach, Jack Riley who is now 87. Listening to these old men recall the golden moment of their youth at a remove of 50 years is touching and inspiring. They remember what they did even if almost everyone else has forgotten their feat. They also realize the worth of what they accomplished. The 1960 US Olympic hockey team is still the only undefeated American team in this sport.

This documentary is obviously a labor of love. It has not received much attention and is not readily available. Even the Internet Movie Database is unaware of its existence.  At $19.95 it’s a bargain. You can buy it here. It can also be bought through Amazon.com.  You don’t have to be a sports fan or a devotee of hockey to be moved by this wonderful depiction of a handful of young men striving to exceed their best at game they loved and for a brief time mastered. You’ll watch it more than once. Highly recommended. February 28th is the 50th anniversary to the day of the team’s gold medal.

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The Obesity Paradox

February 24, 2010

A paper in the February Mayo Clinic Proceeding gives food for thought: Obesity Paradox and Cardiorespiratory Fitness in 12,417 Male Veterans Aged 40 to 70 Years. Everyone is aware of the negative health consequences of obesity. Less familiar is the consistent inverse correlation (the so-called obesity paradox) between mortality and body mass index (BMI) among “patients with heart failure, coronary heart disease, hypertension, peripheral artery disease, type 2 diabetes, and chronic kidney disease. An obesity paradox has been observed in healthier populations as diverse as San Francisco longshoremen, Native American women of the Pima tribe, men from rural Scotland, Nauruan men, and the elderly.” – quotation is from the above article.

The current study sought to examine the obesity paradox further by factoring in fitness. The study built on previous observations that both fitness and a higher BMI were associated with reduced mortality in patients referred for exercise training. The new work looks at both fitness and BMI in the same population of 12,417 men (all veterans age 40 to 70) with known or suspected cardiovascular disease. The men were stratified by BMI. They were also divided into three fitness groups low, moderate, and high. Fitness was defined by exercise ability – METs (metabolic equivalents tasks).

Table four from the study shows the pertinent findings. Fitness was associated with decreased all cause mortality, but so was increased BMI. Thus the best mortality outcomes were in subjects with both increased BMIs and increased exercise tolerance. A hazard ratio (HR) is statistically significant if its 95% confidence interval does not straddle 1. A HR greater than 1 signifies an increased risk, while an HR lower than 1 indicates reduced risk. The reference group (the group to which all others were compared) was the normal BMI high fitness group. A BMI greater than 25 was classified as overweight. A BMI greater than 30 was classified as obese.  High fitness was defined as the ability do more than 10 METs. This is about equivalent to walking up two flights of stairs at a “normal” pace without stopping.

Thus mortality rates were lower in fit overweight and obese male veterans than in equally fit male veterans who were at normal weight. We’re back to the obesity paradox. The authors of this study consider a number of possible reasons for this paradox none of which satisfies. Nobody argues that you should intersperse trips to the gym with frequent stops at Hamburger Heaven so as to be fat and fit, but there seem to be so many examples of the obesity paradox that one must continue to look for an explanation. Maybe the Duchess of Windsor was wrong when she said you could never be too thin. It would be a cause of schadenfreude if all those skinny joggers were running themselves into a premature grave. Regardless, we don’t know as much about what ideal weight should be as we think we do.

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The Ultimate Problem

February 19, 2010

The article below was originally published in 1983. I think it’s still relevant to any current discussion of euthanasia. It also appears under the Seminars in Nephrology Editorials.

Mr. Lincoln (not his name) was a 54-year-old man with metastatic prostatic cancer and chronic renal failure. He had been on dialysis for a number of years and, for a while, had done well. When the diagnosis of metastatic prostatic carcinoma was made, he underwent a bilateral orchiectomy. He refused chemotherapy, however. For a while, he continued to do well despite the obvious presence of cancer. Another hospitalization was required to treat congestive heart failure. During this time the patient lost 30 lb of edema as a result of vigorous dialysis therapy. He had some pain from his tumor, but in general was reasonably comfortable.

Two weeks after his discharge he was readmitted because of abdominal pain. His tumor mass had obviously enlarged. In addition, he had developed an abdominal wound which appeared to be draining feces. Further evaluation demonstrated a fistula between the rectum, the bladder, and the skin. Medical oncology was consulted but felt there was no effective treatment they could offer this man. The patient, who was highly intelligent and in complete possession of all his faculties at all times, was apprised of his situation. He understood that he had an untreatable cancer and that all we could offer was relief of pain. We asked if he would be happier if he were discharged from the hospital with an appropriate prescription for pain relief. He stated that he would prefer to remain in the hospital. We readily agreed to this and then discussed the matter of continuing his dialysis treatment. We told him that, if he wished, we would continue to dialyze him as vigorously as we had in the past, but that if he felt such treatment would only allow him to die a painful death (with the passage of each day his pain became progressively severe) we would stop dialyzing him. We further explained to him that he could take as much time as he wished in making a decision and that regardless of the decision he made he could change his mind. He inquired as to how long we thought he would live and in what condition if we continued dialysis and asked the same information if we were to discontinue this treatment. We gave him our best estimate while explaining that it contained a considerable margin of error.

He thought about his options for about five days, and then told us on rounds that he thought he would prefer to stop dialysis. We told him again that if at any time he changed his mind we would restart his artificial kidney treatment. He said he understood this and thanked us for our concern.

Mr. Lincoln, who was a very proud man, had three children who were very fond of him. Despite this he had avoided them during this terminal phase of his illness. While never expressed, we felt that it was his desire not to be a burden on his family. From talking to his children, it was quite obvious that they did not consider him a burden and wished to spend more time with him. We asked him if he would mind if we called them and informed them of his decision to stop dialysis. He said he had no objection. We called his children and they immediately came to the hospital.

During the last few weeks of his life, Mr. Lincoln had formed an especially close relationship with one of the medical students on my service. He told the student that he would like to have a beer with him. He also expressed a wish to have a bowl of coconut ice cream. The student obtained the ice cream and two cans of beer and they spent part of a Saturday afternoon together drinking the beer, eating the ice cream, and talking. Mr. Lincoln’s daughter was in the hospital that day and asked if she could spend the night with her father. This was arranged and she slept in his room that night. During the evening, the house staff asked Mr. Lincoln if there was anything that he would like to have. He said that he would really enjoy a glass of orange juice. This was obtained and he drank it with relish. Shortly thereafter, he went to sleep with his daughter in the room. At 6:00 in the morning the nurses noted that he was dead. It had been three days since his last dialysis. On Saturday morning, his serum potassium was 6.7 mEq/1. While we can’t be certain, it seems highly likely that Mr. Lincoln died from the cardiac effects of hyperkalemia. The source of the excess potassium, of course, was dietary.

In thinking about Mr. Lincoln, a number of questions keep recurring. I have the answers to none of them, but they are important questions nonetheless. Did Mr. Lincoln die as the result of euthanasia? Did he commit suicide? Did he die from natural causes? Clearly, if he had not stopped dialysis and had not consumed foods high in potas¬sium he would not have died when he did. As I have said, he was highly intelligent, and while we did not discuss this, I have no doubt that he was aware that orange juice is high in potassium. I know we were also aware, though we were not thinking about that when we gave him the juice. If we had given him potassium intravenously, that clearly would have been euthanasia. How different is it to give him food and drink high in potassium when he had no renal function and was not receiving dialysis treatment? Giving him cyanide by mouth would have been legally and morally wrong, but giving him dietary potassium seems to be all right.

Last, given that Mr. Lincoln had untreatable cancer, he was in a sense fortunate to have chronic renal failure. He had the option to stop dialysis and die peacefully and at a time of his choosing. If he had had metastatic carcinoma without chronic renal failure, his death would have taken a considerably longer time and been associated with much more pain than he experienced. Regardless of his wishes, we would have only been able to treat his pain while waiting for his disease to kill him. The problems I am raising are as obvious as their solutions are elusive. We can relieve pain and suffering, but only to a point. The patient can, in essence, take his own life when he has widespread cancer if he is fortunate enough to have a disease like chronic renal failure. He cannot take it by a more active course. I cannot even begin to competently discuss a problem which has troubled theologians and philosophers for centuries. But the distinctions between what is permissible and what is not sometimes appear precious. All I do know with certainty is that we helped Mr. Lincoln and that he knew we were helping him and was grateful for our efforts. I feel good about the way things worked out.

Originally published:
Kurtzman NA: The Ultimate Problem. Sem Nephrol 3:75, 1983.

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Dietary Salt Reduction and Cardiovascular Disease

February 12, 2010

A paper in the New England Journal of Medicine, Projected Effect of Dietary Salt Reductions on Future Cardiovascular Disease, concludes that “Modest reductions in dietary salt could substantially reduce cardiovascular events and medical costs and should be a public health target.” This conclusion is based on the use of a very complicated computer model of coronary heart disease. It extrapolates from this model to the population at large, ie, those without heart disease, and reaches a conclusion that everyone would benefit from dietary salt reduction.

It further posits that “Reducing dietary salt lowers…the risk of cardiovascular disease. Here’s the reference the authors of the study cite to support this conclusion. Effect of longer-term modest salt reduction on blood pressure. As you can see there’s nothing in this paper to support this conclusion other than speculation that such a result should follow reduced dietary salt. There are no data in the paper to support this view. The view may be correct, but this reference doesn’t show it’s so. Basically, what the authors assume is that healthy subjects will sicken from a salt intake greater than about 100 mmoles/day and that the higher salt intake goes the greater the resultant ill health. Their health will degrade goes the argument because they will develop hypertension.

It has been clear for decades that part of the population is salt sensitive. Such people have substantial increases in blood pressure as dietary salt increases. The subsequent hypertension they may develop is a major cause of stroke and cardiovascular disease. They would be much better off to reduce their salt intake. Likewise, patients with heart, kidney, and liver disease would also benefit from reduced salt intake. But we also know that a significant part of the population is salt insensitive. Despite large intakes of salt these lucky individuals do not increase their blood pressure or suffer deleterious effects from large salt intakes.

The authors of the NEJM study conclude that not only will there be great public health benefits from reducing dietary salt, but that there will be substantial cost savings resulting from this decrease in salt intake and the resultant decrease in cardiovascular disease. Since their conclusions flow from a complex model it’s hard to know how much of these conclusions are valid. I suspect that the benefit they anticipate is less than they believe for two reasons. First there’s the large salt insensitive part of the population I’ve already mentioned. Second is that there are no data showing that cardiovascular events significantly decrease when an undifferentiated population decreases its salt intake. There may well such a benefit, but it’s speculative and likely much smaller than these authors think.

Regardless of the final resolution of this issues there’s another agenda at work in this article. It’s more political than scientific. Having decided that a reduction in salt intake is in the best interests of the public the authors conclude that government coercion is the only way to force a lower salt diet on an unwilling public. “Changes in behavior are notoriously difficult to achieve, and attempts to lower dietary salt intake on an individual basis have largely proved to be ineffective.” Here they stop being scientists and become social engineers. They want the federal government to intervene and regulate salt. They specifically mention the Food and Drug Administration. They obviously think they know better than those who disregard their learned advice and that these unwilling citizens should be forced to do what’s best for them regardless of their wishes to the contrary.

This is the all too typical presumption of people who have expertise in one special area and who think this entitles them to competence in other areas where their opinion or knowledge is no better than that of anyone else. What they’re saying is that educating the public about the dangers of high salt intake is only good if the public does as told. If they don’t they must be forced. Personal liberty is not an idle abstruse point; it’s a central pillar of a free society. That the NEJM saw nothing strange about this view, indeed they published a supporting editorial, tells us a lot about the Journal and about those who have our “best interests” at heart. The lack of faith in education shown by a periodical whose only function is education is staggering.  Who will save us from our saviors?

William Buckley famously said that he’d rather be governed by the first 1000 names in the Boston telephone directory than the Harvard faculty. I wonder if these same 1000 Bostonians might make better public health decisions than the editorial board of the NEJM.

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Simon Boccanegra in HD

February 7, 2010

Verdi’s majestically flawed masterpiece was televised February 6, 2010. Simon Boccanegra stays in the repertory because of it’s glorious music and its great title role. It always fails to completely satisfy because of its insane libretto and because of it’s imperfect structure. Piave’s libretto makes that of Il Trovatore look like the exemplar of the well made play. Boito’s revision made the work worse – from the standpoint of dramatic structure – despite providing the opera with it’s greatest scene; one that by itself equals Verdi’s best . The council chamber scene that concludes the first act is a tour de force. It’s so good that it dwarfs the succeeding two acts which while containing much beautiful music are a steady descent into ever deepening gloom.

Boccanegra is one of Verdi’s greatest baritone roles, which is to say that it’s one of opera’s greatest baritone roles. Verdi’s wrote for a special type of baritone – one who could sustain a high tessitura while maintaining a dark timbre and a sound that could fill the house. It’s not hard for a tenor to sing Verdi’s baritones because they’re written so high. But what a tenor can’t do is sound like a baritone. I can understand why Placido Domingo would want to sing Simon Boccanegra and I can understand why the world’s great opera houses, like the Met, would let him do so; he’s Placido Domingo. But even without the top fifth of the tenor range he’s still a tenor. He doesn’t have the sound needed for Boccanegra. What we got from his portrayal was a very solid effort, remarkable for a 68 year old singer, but one that remains an earnest vanity project. Notice the 68 – Domingo is great considering he’s an old man. If it were Pablo Domingo from Ecuador as Boccanegra he’d be singing the role in Ecuador.

The rest of the production was assembled as a satellite around Domingo’s star. Canadian soprano Adrianne Pieczonka, best know for her Wagnerian roles, was Amelia/Maria. She has a strong well produced voice that was more than adequate for her role. What she lacked was the Verdian sheen necessary to fully realize his heavier roles.

Marcello Giordani screamed his way through the first performance of this run. He managed to sing a little more during the televised show which was the last of the series. Nevertheless, he still puts enormous pressure on his voice. Gabriele Adorno is perhaps the most awkwardly written of Verdi’s major tenor parts. It has a high tessitura and spend a lot of time in the passagio. Consequently is requires a tenor who can make his way through its difficulties without sounding like a victim of the Inquisition. Richard Tucker was prefect in the role. Giordani sounded like he expected the Spanish inquisition despite the Monty Python’s declaration that no one does.

James Morris, another sexagenarian, is not the singer he once was. He got through the opera’s mostly thankless bass role without either embarrassment or distinction. Stephen Gaertner provided the performance’s only true baritone sound as the nefarious poisoner Paolo. The revival of Giancarlo del Monaco’s production looks good, though the sets and costumes are about a 100 years beyond 14th century Genoa. James Levine looking very frail nonetheless conducted a fiery reading of Verdi’s beautiful score. The council chamber scene was as impressive in practice as it is on the page.

Video director Barbara Willis Sweete is still addicted to extreme closeups. Watching both Domingo and Morris sweat their way through the opera’s conclusion would satisfy neither Aristotle or Samuel Taylor Coleridge. Back off.

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