Showing posts with label Endocrinology. Show all posts
Showing posts with label Endocrinology. Show all posts

Wednesday, April 13, 2011

Statins slightly increase risk of cataracts, liver dysfunction, kidney failure and muscle weakness

Statins do NOT prevent a long list of diseases

Statins were not significantly associated with risk of Parkinson’s disease, rheumatoid arthritis, venous thromboembolism, dementia, osteoporotic fracture, gastric cancer, colon cancer, lung cancer, melanoma, renal cancer, breast cancer, or prostate cancer.

Statins may decrease risk of esophageal cancer

Statin use was associated with decreased risks of oesophageal cancer.

Statins slightly increase the risk of liver dysfunction, kidney failure, muscle weakness and cataracts

Statin use was associated with increased risks of moderate or serious liver dysfunction, acute renal failure, moderate or serious myopathy, and cataract.

Is the risk the same with all statins?

Adverse effects were similar across statin types for each outcome except liver dysfunction where risks were highest for fluvastatin.

A dose-response effect was apparent for acute renal failure and liver dysfunction. All increased risks persisted during treatment and were highest in the first year.

How long does the risk last?

After stopping treatment the risk of cataract returned to normal within a year in men and women. Risk of acute renal failure returned to normal within 1-3 years in men and women, and liver dysfunction within 1-3 years in women and from three years in men.

What was the NNT and NNH?

Based on the 20% threshold for cardiovascular risk, for women the NNT with any statin to prevent one case of cardiovascular disease over five years was 37 and for oesophageal cancer was 1266 and for men the respective values were 33 and 1082.

In women the NNH for an additional case of acute renal failure over five years was 434, of moderate or severe myopathy was 259, of moderate or severe liver dysfunction was 136, and of cataract was 33. Overall, the NNHs and NNTs for men were similar to those for women, except for myopathy where the NNH was 91.

Conclusion

Claims of unintended benefits of statins, except for oesophageal cancer, remain unsubstantiated, although potential adverse effects at population level were confirmed and quantified.

Interestingly, the BMJ abstract did not mention increased diabetes risk that was reported in a previous study published in The Lancet.

References:
Balancing the intended and unintended effects of statins. BMJ 2010; 340:c2240 doi: 10.1136/bmj.c2240 (Published 20 May 2010).
Image source: Simvastatin. Wikipedia, public domain.

Tuesday, April 5, 2011

Gout update: New drugs for an old disease

Febuxostat is a non-purine-analogue inhibitor of xanthine oxidase that opened a new era in the treatment of gout.

Modified uricases

The use of modified uricases to rapidly reduce serum urate concentrations in patients with otherwise untreatable gout is progressing. Pegloticase, a pegylated uricase, is in development.

Drugs in development

Transport of uric acid in the renal proximal tubule and the inflammatory response to monosodium urate crystals (shown above) are targets for potential new treatments.

Several pipeline drugs for gout related to the targets above include:

- selective uricosuric drug RDEA594
- various interleukin-1 inhibitors

References:
Gout therapeutics: new drugs for an old disease. The Lancet, Volume 377, Issue 9760, Pages 165 - 177, 8 January 2011.
Image source: Spiked rods of uric acid (MSU) crystals from a synovial fluid sample photographed under a microscope with polarized light. Wikipedia, public domain.

Friday, March 18, 2011

What drug to add to maximal metformin therapy for diabetes?

Metformin is the recommended initial drug therapy for patients with type 2 diabetes mellitus (DM). However, the optimal second-line drug when metformin monotherapy fails is unclear.

All noninsulin antidiabetic drugs were associated with similar HbA1c reductions but differed in their associations with weight gain and risk of hypoglycemia.

The different classes of drugs were associated with similar HbA1c reductions (range, 0.64%-0.97%) compared with placebo.

Noninsulin antidiabetic drugs and their effect on body weight:

- thiazolidinediones, sulfonylureas, and glinides were associated with weight gain (range, 1.77-2.08 kg)

- glucagon-like peptide-1 analogs, alpha-glucosidase inhibitors, and dipeptidyl peptidase-4 inhibitors were associated with weight loss or no weight change

Sulfonylureas and glinides were associated with higher rates of hypoglycemia than with placebo.

References:
Image source: Metformin. Wikipedia, public domain.

Thursday, February 17, 2011

Screening for Familial Hypercholesterolemia - CDC Expert Commentary



Screening for Familial Hypercholesterolemia - CDC Expert Commentary (video). Renée M. Ned, PhD, MMSc discusses the benefits of cascade screening to identify familial hypercholesterolemia, a common genetic disorder that causes high levels of low-density lipoprotein (or LDL) cholesterol.

Thursday, February 3, 2011

Heart numbers to know - by Cleveland Clinic

Cleveland Clinic has been ranked the number one hospital in the U.S. for heart disease and heart surgery for the last 19 years. They must know what they are talking about when selecting the "heart numbers to know". This is the list by the cardiologist Dr. Richard Krasuski and the Clinic Twitter account.

Knowing your risk for heart disease depends on knowing and understanding some important numbers:

- Blood pressure should be less than 120/80 mm Hg

- Fasting blood sugar should be less than 100 mg/dL

- Total cholesterol less than 200 mg/dL

- LDL (bad cholesterol) less than 100 mg/dL, HDL (good) greater than 40 mg/dL

- Waist circumference should be less than 40 inches for men and less then 35 inches for women

- Body Mass Index (BMI) should be between 18.5 and 25. Calculate your BMI here: http://bit.ly/glMJE5

I worked at the Cleveland Clinic until 2008 and at that time the imposing building of the Heart & Vascular Institute was just getting completed:


Cleveland Clinic Heart & Vascular Institute

Image source: Cleveland Clinic logo.

Monday, January 31, 2011

Vitamin D receptor activation with paricalcitol decreases albuminuria in type 2 diabetes

Despite treatment with renin—angiotensin—aldosterone system (RAAS) inhibitors, patients with diabetes have increased risk of progressive renal failure that correlates with albuminuria.

281 patients with type 2 diabetes and albuminuria who were receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers were enrolled in this study.

Patients were assigned to receive 24 weeks' treatment with:

- placebo
- 1 μg/day paricalcitol
- 2 μg/day paricalcitol

Paricalcitol (trade name Zemplar, Abbott Laboratories) is an analog of calcitriol, the active form of vitamin D.

The primary endpoint was the percentage change in mean urinary albumin-to-creatinine ratio (UACR).

The change in urinary albumin-to-creatinine ratio (UACR) was: −14% in the 1 μg paricalcitol group, and −20% in the 2 μg paricalcitol group.

The addition of 2 μg/day paricalcitol to RAAS inhibition safely lowers albuminuria in patients with diabetic nephropathy, and could be a novel approach to lower renal risk in diabetes.

References:
Selective vitamin D receptor activation with paricalcitol for reduction of albuminuria in patients with type 2 diabetes (VITAL study): a randomised controlled trial. The Lancet, Volume 376, Issue 9752, Pages 1543 - 1551, 6 November 2010.
Image source: Paricalcitol, Wikipedia, public domain.

Thursday, December 30, 2010

Laughter May Increase Appetite

A hearty laugh and a moderate workout may have more in common than anyone thought.

Both affect the appetite hormones in much the same way:

- When leptin goes down, it increases appetite
- When ghrelin goes up, it increases appetite

That is what typically happens after moderate exercise.

Leptin (from Greek, leptos, meaning thin) is a protein hormone that plays a key role in regulating energy intake and expenditure, including appetite and metabolism. Leptin acts on receptors in the hypothalamus of the brain where it inhibits appetite.

Ghrelin is a hormone that stimulates hunger. The name is based on its role as a growth hormone-releasing peptide, with reference to the root "ghre", meaning to grow. It is produced by the cells lining the fundus of the stomach and epsilon cells of the pancreas. It is considered the counterpart of the hormone leptin, produced by adipose tissue.

Twitter comments:

@LJaneTn Fat and Funny?

@doctorwhitecoat This explains why I'm always so hungry.

@scanman That explains why I eat too much when I party with friends.

Image source: Wikipedia, public domain.

Tuesday, December 14, 2010

Correcting Vitamin D Deficiency May Decrease Risk of Heart Disease

In a recent study, 9,400 patients had an average vitamin D level of 19.3 nanograms per milliliter - levels of 30 are generally considered "normal". At their next follow-up visit, 50% of patients had raised their vitamin D levels to above 30 nanograms per milliliter.

Compared with patients whose vitamin D levels were still low, patients who raised their vitamin D levels were 33% less likely to have a heart attack, 20% less likely to develop heart failure, and 30% less likely to die between the two visits (source: WebMD).

"While normal has generally been considered to be 30, some people have suggested 40 or 50 is better. People who increased their vitamin D blood level to 43 nanograms per milliliter had the lowest rates of heart disease and stroke. But increasing it beyond that, say to 60 or 70, offered no greater benefit."

One of the BMJ blogs calls vitamin D "the elixir of life", but it all starts to sound a bit too good to be absolutely true.


Serum 25(OH)D.

The circulating half-life of 25(OH)D is 2 weeks. This is the best test to determine vitamin D status. A 25(OH)D level of less than 32 ng/mL is considered vitamin D insufficient because intestinal calcium absorption is optimized at levels above 32 ng/mL.

A 25(OH)D level of less than 15 or 20 ng/mL have been used to define vitamin D deficiency.

Parathyroid hormone levels start to rise at 25(OH)D levels below 31 ng/mL, which is another marker of vitamin D insufficiency. Although not always required for the diagnosis of vitamin D insufficiency, a serum PTH may be used to help establish the diagnosis of vitamin D insufficiency.

The word vitamin was originally derived from Funk's term "vital amine."

References:
Vitamin D Supplements Lower Heart Disease Risk. WebMD.

Tuesday, December 7, 2010

Following DASH Diet Improves Brain Activity in Overweight Adults

A new study suggest that the DASH diet in combination with regular exercise improves mental activity by 30% in overweight adults compared with those who didn’t diet or exercise. The DASH diet was developed for the Dietary Approaches to Stop Hypertension (DASH) study and emphasizes low-fat dairy products and low-cholesterol foods as well as carbohydrates and fruits and vegetables.

Researchers say high blood pressure affects about 50% of adults aged 60 and older and increases the risk of Alzheimer’s disease and other forms of mental decline like dementia.

These are 5 healthy lifestyle factors associated with a lower risk of developing high blood pressure:

1. Healthy weight: body mass index (BMI) of less than 25.
2. Daily exercise: average of 30 minutes of vigorous exercise per day.
3. Heart-healthy diet (DASH).
4. Moderate alcohol use.
5. Use non-narcotic pain relievers less than once per week.

A table to show the impact of lifestyle interventions on blood pressure http://bit.ly/johjzs - Great for patient education.
Related: What is the best diet in the world? DASH Diet, according to the latest review. TIME, 2011.

Monday, November 8, 2010

Liraglutide (Victoza) superior to sitagliptin (Januvia) for reduction of HbA1c in diabetics


Action of DPP-4 inhibitors. Note that DPP-4 normally inactivates GLP-1. DPP-4 inhibitors block DPP-4 which in turn leaves GLP-1 active. Click to enlarge the figure. Created with Gliffy.

What is Glucagon-like peptide-1 (GLP-1)?

Glucagon-like peptide-1 (GLP-1) is a GI peptide that stimulates insulin secretion (similar to sulfonylureas). GLP-1 also inhibits glucagon release, gastric emptying and food absorption. GLP-1 and another similar peptide are called incretins. As noted above, incretins have a dual action which leads to lowering blood glucose:

1. Stimulate insulin release
2. Inhibit glucagon release

Exenatide (Byetta) is a GLP-1 receptor agonist approved for adjunctive therapy for patients with DM 2 who are not well controlled on oral agents. It is available only as injections and has to be administered twice daily.

DPP-4 inhibitors, or gliptins, increase GLP-1 levels by blocking the enzyme which inactivates GLP-1. The enzyme is called DPP-4 (dipeptidyl peptidase-4). They act similarly to Byetta (see figure above) but have the big advantage to be available in oral form (pills). Gliptins used for treatment of DM2 include sitagliptin (Januvia) and vildagliptin (Galvus).

What is Liraglutide?

Liraglutide (Victoza) is a long-acting glucagon-like peptide-1 (GLP-1) analog that was developed by Novo Nordisk for the treatment of type 2 diabetes. Liraglutide has a half-life after subcutaneous injection of 11–15 hours, making it suitable for once-daily dosing (in contrast to Byetta's twice daily).


Liraglutide. Image source: Wikipedia, public domain.

Liraglutide (Victoza) superior to sitagliptin (Januvia) for reduction of HbA1c in diabetics

This Lancet study assessed the efficacy and safety of the human GLP-1 analogue liraglutide versus the DPP-4 inhibitor sitagliptin, as adjunct treatments to metformin, in individuals with type 2 diabetes who did not achieve adequate glycaemic control with metformin alone.

More than 600 participants (aged 18—80 years) with type 2 diabetes mellitus who had inadequate glycaemic control (glycosylated haemoglobin [HbA1c] 7·5—10·0%) on metformin (more than 1500 mg daily) were enrolled.

Participants were randomly allocated to receive 26 weeks' treatment with 1·2 mg or 1·8 mg subcutaneous liraglutide once daily, or 100 mg oral sitagliptin once daily.

Greater lowering of mean HbA1c (8·5% at baseline) was achieved with 1·8 mg liraglutide (−1·50%) and 1·2 mg liraglutide (−1·24%) than with sitagliptin (−0·90%).

Nausea was more common with liraglutide (27%) on 1·8 mg. Minor hypoglycaemia was recorded in about 5% of participants in each treatment group.

Liraglutide was superior to sitagliptin for reduction of HbA1c, and was well tolerated with minimum risk of hypoglycaemia. These findings support the use of liraglutide as an effective GLP-1 agent to add to metformin.

References:

Tuesday, November 2, 2010

Lowering Triglycerides With Exercise - Mayo Clinic Video



Mayo Clinic | October 22, 2010: Instead of taking medicine to lower triglycerides, most people can lower that number simply by moving more.

Friday, October 29, 2010

Statins Use in Presence of Elevated Liver Enzymes: What to Do?

The beneficial role of statins in primary and secondary prevention of coronary heart disease has resulted in their frequent use in clinical practice.

However, safety concerns, especially regarding hepatotoxicity, have driven multiple trials, which have demonstrated the low incidence of statin-related hepatic adverse effects. The most commonly reported hepatic adverse effect is the phenomenon known as transaminitis, in which liver enzyme levels are elevated in the absence of proven hepatotoxicity.

"Ttransaminitis" is usually asymptomatic, reversible, and dose-related.


Lovastatin, a compound isolated from Aspergillus terreus, was the first statin to be marketed for lowering cholesterol. Image source: Wikipedia, public domain.

The increasing incidence of chronic liver diseases, including nonalcoholic fatty liver disease and hepatitis C, has created a new challenge when initiating statin treatment. These diseases result in abnormally high liver biochemistry values, discouraging statin use.

A PubMed/MEDLINE search of the literature (1994-2008) was performed for this Mayo Clinic Proceedings review. The review supports the use of statin treatment in patients with high cardiovascular risk whose elevated aminotransferase levels have no clinical relevance or are attributable to known stable chronic liver conditions.

References:
Statins in the Treatment of Dyslipidemia in the Presence of Elevated Liver Aminotransferase Levels: A Therapeutic Dilemma. Rossana M. Calderon, MD, Luigi X. Cubeddu, MD, Ronald B. Goldberg, MD and Eugene R. Schiff, MD. Mayo Clinic Proceedings April 2010 vol. 85 no. 4 349-356.

Monday, October 25, 2010

What's new in endocrinology from UpToDate

35% of UpToDate topics are updated every four months. The editors select a small number of the most important updates and share them via "What's new" page. I selected the brief excerpts below from What's new in endocrinology:

Osteoporosis

Denosumab (Prolia)

Denosumab is a fully human monoclonal antibody that specifically targets a ligand known as RANKL (that binds to a receptor known as RANK) which is a key mediator of osteoclast formation, function, and survival. Denosumab was approved for the treatment of postmenopausal women with osteoporosis at high risk for fracture (history of osteoporotic fracture, multiple risk factors for fracture) or patients who have failed or are intolerant of other available osteoporosis therapies. Denosumab inhibits the formation, function, and survival of osteoclasts. It decreases bone resorption, increases bone mineral density (BMD), and reduces the risk of fracture.

Teriparatide (Forteo)

Teriparatide (parathyroid hormone) did not accelerate fracture healing in postmenopausal women with distal radial fractures.

Transdermal teriparatide patch worked as well as teriparatide injection in postmenopausal women with osteoporosis.

Orlistat (Xenical, Alli) in obesity

Severe liver injury has been reported rarely with the use of orlistat (13 reports). Over the ten year period of the review, an estimated 40 million people worldwide used orlistat.

References:
What's new in endocrinology and diabetes mellitus. UpToDate.
Image source: Flickr, Creative Commons license.

Tuesday, October 5, 2010

Beyond statins: Thyromimetic eprotirome decreases LDL

Dyslipidemia increases the risk of atherosclerotic cardiovascular disease and is incompletely reversed by statin therapy alone in many patients. Thyroid hormones lower levels of serum low-density lipoprotein (LDL) cholesterol and has other potentially favorable actions on lipoprotein metabolism. Consequently, thyromimetic drugs hold promise as lipid-lowering agents if adverse effects can be avoided.

In this 12-week trial, the thyroid hormone analogue eprotirome was associated with decreases in levels of atherogenic lipoproteins in patients receiving treatment with statins.

Similar reductions were seen in levels of serum LDL, apolipoprotein B, triglycerides, and Lp(a) lipoprotein. No change in levels of serum thyrotropin or triiodothyronine was detected, although the thyroxine level decreased in patients receiving eprotirome.

References:
Image source: Wikipedia, public domain.

Monday, September 13, 2010

People who get less than 6 hours sleep per night have an increased risk of dying prematurely

People who get less than 6 hours sleep per night had an increased risk of dying prematurely in a recent study. Those who slept for less than that amount of time were 12% more likely to die early, though researchers also found a link between sleeping more than 9 hours and premature death.

The study aggregated decade-long studies from around the world involving more than 1.3 million people and found "unequivocal evidence of the direct link" between lack of sleep and premature death.

Just one sleepless night can hamper the body's ability to use insulin to process sugar in the bloodstream. Insulin sensitivity is not fixed in healthy people, but depends on the duration of sleep in the preceding night.

"Society pushes us to sleep less and less," one of the study investigators said, adding that about 20% of the population in the United States and Britain sleeps less than 5 hours.

Adults typically need between 7 and 9 hours sleep a night. If you sleep little, you can develop diabetes, obesity, hypertension and high cholesterol.

Image source: A halo around the Moon. Wikipedia, GNU Free Documentation License.

Thursday, September 9, 2010

Lipoprotein-associated phospholipase A2 increases risk of coronary disease

Lipoprotein-associated phospholipase A2 (Lp-PLA2), an inflammatory enzyme expressed in atherosclerotic plaques, is a therapeutic target being assessed in trials of vascular disease prevention.

Lp-PLA2 activity and mass each show continuous associations with risk of coronary heart disease, similar in magnitude to that with non-HDL cholesterol or systolic blood pressure.



Lipoprotein structure (chylomicron). Image source: Wikipedia, GNU Free Documentation License.

References:

Tuesday, August 31, 2010

For people with congestive heart failure, a hot dog can trigger a trip to the hospital due to excessive salt

The average daily salt intake in America is one and 1/2 teaspoon a day. This is 3,400 milligrams of sodium a day, or 1,100 milligrams more then the recommended maximum.

For people with congestive heart failure, a salty hot dog can trigger a trip to the hospital.

The experts say the new target for sodium intake should be set at 1,500 milligrams daily.

In a previous study, reducing dietary salt by 3 gm per day (1200 mg of sodium per day) was projected to reduce the annual number of new cases of coronary heart disease by 60,000 to 120,000, stroke by 32,000 to 66,000, and myocardial infarction by 54,000 to 99,000 and to reduce the annual number of deaths from any cause by 44,000 to 92,000. Such an intervention would be more cost-effective than using medications to lower blood pressure in all persons with hypertension.

77% of the salt in the American diet comes from processed food. Only 6% is shaken out at the table, and only 5% is sprinkled during cooking.

Once people cut back on salt -- whether or not they know they are doing it -- they begin to prefer less salt in their food. This happens in a matter of weeks.

For example, alarmed by high death rates from strokes, Portugal plans to decrease salt in bread, blamed for high blood pressure. Portugal has one of the highest mortality rates from strokes in Europe - double that in Spain and 3 times that in France. http://is.gd/ndNv

The daily salt intake in Portugal is a staggering 12.3 grams (ranging from 5.2 to 24.8 gm) http://is.gd/ndQq

References:
Americans Need Help Shaking The Salt Habit - Shots - NPR Health News Blog.

Tuesday, August 10, 2010

Glycated hemoglobin as a diagnostic test for diabetes predicts mortality more accurately than fasting glucose

Fasting glucose is the standard measure used to diagnose diabetes in the United States. Recently, glycated hemoglobin was also recommended for this purpose.

The glycated hemoglobin value at baseline was associated with newly diagnosed diabetes and cardiovascular outcomes.

For glycated hemoglobin, values of less than 5.0%, 5.0-5.5%, 5.5-6.0%, 6.0-6.5%, and 6.5% or greater, the hazard ratios for diagnosed diabetes were 0.52, 1.00, 1.86, 4.48, and 16.47, respectively.

For coronary heart disease, the hazard ratios were 0.96, 1.00, 1.23, 1.78, and 1.95, respectively. The hazard ratios for stroke were similar.

In contrast, glycated hemoglobin and death from any cause were found to have a J-shaped association curve.

The association between the fasting glucose levels and the risk of cardiovascular disease or death from any cause was not significant.

In this community-based population of nondiabetic adults, glycated hemoglobin was associated with a risk of diabetes and more strongly associated with risks of cardiovascular disease and death from any cause as compared with fasting glucose. These data add to the evidence supporting the use of glycated hemoglobin as a diagnostic test for diabetes.

References:
Image source: OpenClipArt.org, public domain.

Wednesday, July 21, 2010

Increasing Diet Polyunsaturated Fat in Place of Saturated Fat Reduces Risk of Coronary Heart Disease

Reduced saturated fat (SFA) consumption is recommended to decrease coronary heart disease (CHD), but there is an absence of strong supporting evidence from randomized controlled trials (RCTs) of clinical CHD events and few guidelines focus on any specific replacement nutrient. Additionally, some public health groups recommend lowering or limiting polyunsaturated fat (PUFA) consumption, a major potential replacement for SFA.

The overall pooled risk reduction was 19% (RR = 0.81), corresponding to 10% reduced CHD risk (RR = 0.90) for each 5% energy of increased PUFA.

These findings provide evidence that consuming PUFA in place of SFA reduces CHD events in RCTs. This suggests that rather than trying to lower PUFA consumption, a shift toward greater population PUFA consumption in place of SFA would significantly reduce rates of CHD.

References:
Image source: Varieties of meat, Wikipedia, public domain.

Tuesday, July 20, 2010

Start metformin early when diabetes type II is first diagnosed

Initiating metformin soon after diabetes diagnosis and while A1C is low might preserve β-cell function, prolong the effectiveness of metformin, reduce lifetime glycemic burden, and prevent diabetes complications.

These findings support the current treatment algorithm for hyperglycemia management that recommends metformin initiation when diabetes is first diagnosed.

References:
Secondary Failure of Metformin Monotherapy in Clinical Practice. Diabetes Care March 2010 vol. 33 no. 3 501-506.