A look at the latest research

PREGNANCY COMPLICATIONS Associated With Thyroid Disease

Women with thyroid diseases are at a greater risk for developing complications during pregnancy, labor, or delivery, a recent study published in the Journal of Clinical Endocrinology and Metabolism shows.

Thyroid conditions affect up to 4% of all pregnancies, with primary hypothyroidism being the most prevalent disease, according to researchers led by Tuija Männistö, MD, PhD, at the National Institute of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Using thyroid disease and outcome data derived from electronic medical records of 223,512 singleton pregnancies from the U.S. Consortium on Safe Labor, the scientists were able to make the connections between the thyroid conditions and obstetrical complications.

Women suffering from both hypothyroidism and hyperthyroidism had increased odds of complications such as preeclampsia, preterm birth, induction, and ICU admission, to name a few.

The authors concluded that the results indicate that thyroid diseases are associated with significant increases in morbidity during pregnancy, but acknowledged that given the lack of information on treatment during pregnancy, they were unable to explore whether inadequate treatment was the cause or whether some of the risk is due to thyroid disease itself.
— Derek Bagley

PRECOCIOUS PUBERTY Caused by Gene Mutation

Central precocious puberty, which causes children to undergo puberty earlier than they normally would, can be caused by a gene that scientists have recently identified in familial cases, according to a study recently published in the New England Journal of Medicine and presented at The Endocrine Society’s annual meeting in San Francisco.

Girls usually begin puberty between ages 8 and 13, and boys from 9 to 14, but researchers, led by Ursula B. Kaiser, MD, found that loss-of-function mutations of the gene MKRN3 cause girls and boys to start puberty before ages 8 and 9, respectively. These mutations cause disease when inherited exclusively from the father and seem to release the brake that inhibits the secretion of the reproductive hormones in childhood. Early puberty can result in a number of problems, such as short stature, behavioral disorders during adolescence, and increased risk of cardiovascular disease.

The scientists concluded that testing for the MKRN3 mutation could be useful, leading to a better understanding of what controls puberty and facilitating the genetic counseling of central precocious puberty.
— Derek Bagley

PREORDERING SCHOOL LUNCH Fosters Good Choices

Elementary school students who have the option of preordering their lunch are more likely to choose healthier options than those who order on lunchlines, say researchers at Cornell University in a research letter appearing in the May 3 issue of JAMA Pediatrics.

Over a period of four weeks, 272 students in 14 classrooms were randomly assigned to different procedures. In the first week, all students preordered lunch as usual. In the third week, students in four classrooms discontinued preordering, but resumed preordering in the final week. In the fourth week, students in five classrooms discontinued preordering. Students in five classrooms continued to preorder throughout the entire study.

After analyzing sales records and entrée choice, the researchers, led by Brian Wansink, found that 29% of the students chose healthier meals when they preordered, but only 15% chose healthier meals when they ordered on lunch lines. When purchasing lunch in the lunch line, 48% fewer students selected a healthy entrée and 21% additional students selected a less healthy entrée. In their letter, the researchers attribute this phenomenon to “hungerbased, spontaneous selection” as affected by the sight and smell of tasty, but ultimately less healthy, foods.
— Terri D’Arrigo

AIR POLLUTION and Atherosclerosis

Air pollution from cars, power plants, and other sources of combustion may raise the risk of cardiovascular disease and stroke by promoting atherosclerosis, say researchers at the multicenter Multi-Ethnic Study of Atherosclerosis.

In a study published in the April issue of PLOS Medicine, a team led by the University of Michigan’s Sara Adar, ScD, MHS, and the University of Washington’s Joel Kaufman, MD, MPH, examined changes in the thickness of the right carotid arteries of 5,362 men and women older than 45 in six metropolitan areas — Baltimore, Chicago, Los Angeles, New York, St. Paul, and Winston-Salem — using neck ultrasounds collected roughly 2.5 years apart. In the year leading up to the first ultrasound and for the years between the first and second ultrasounds, the researchers used air samples collected outside the homes and in the communities of the study participants to determine local concentrations of fine-particulate air pollution — air pollution containing particles with a diameter of ⅓0 the width of a human hair.

At follow-up, the researchers found that the walls of the participants’ carotid arteries increased 14 micrometers per year on average, and that thickening progressed faster among participants who lived in areas with the highest levels of air pollution. In their conclusion, the researchers write that their results support the theory that fine-particulate air pollution may be associated with the progression of atherosclerosis.
— Terri D’Arrigo

TWO OSTEOPOROSIS DRUGS Are Better Than One

Combining two osteoporosis drugs helps maintain bone density in postmenopausal women better than either drug alone, say researchers at Massachusetts General Hospital in Boston.

In a study appearing online in the May 15 issue of Th e Lancet, a team led by Benjamin Leder, MD, compared the effects of two injectable drugs, denosumab (Prolia) and teriparatide (Forteo), taken separately or together, in 94 post-menopausal women with osteoporosis. Denosumab inhibits osteoclasts, cells that remove bone tissue, and teriparatide stimulates osteoblasts, cells responsible for bone formation.

The team divided 94 study participants into three groups. One group received 60 mg of denosumab every six months, one group received 20 mcg of teriparatide daily, and one group received both treatments. The team measured the women’s bone density at three months, six months, and the study’s end, and found that women who received combined drug therapy experienced a 9.1% increase in bone density in their lumbar spines (lower backs), compared to a 6.2% increase among those who received teriparatide only, and a 5.5% increase among those who received only denosumab.

Although the researchers call for further study to assess reductions in fracture risk and explore the effects of different doses, they note that their findings suggest that combining these two drugs may be a useful option for women with osteoporosis.
— Terri D’Arrigo

FATTY LIVER and Incidence of Diabetes

Change in an individual’s fatty liver status over time leads to “markedly variable” risks of incident diabetes, according to a recent Korean study published in the Journal of Clinical Endocrinology and Metabolism.

Non-alcoholic fatty liver disease (NAFLD) occurs often in obese people and is one of the most common chronic liver diseases in the world. Fatty liver is associated with metabolic syndrome and type 2 diabetes.

Scientists, led by Ki-Chul Sung, MD, PhD, of Sungkyunkwan University in South Korea, studied a Korean occupational cohort comprising 13,218 people with no diabetes at baseline. Fatty liver status was measured using an ultrasound at baseline and then again after a five-year followup. The assessments placed the fatty liver statuses in three categories: absent, mild, and moderate/severe.

Over the course of five years, NAFLD resolved in 828 people, developed in 1,640, and progressed from mild to moderate or severe in 324. Out of the 828 whose fatty liver disappeared, 12 developed incident diabetes, suggesting that there is no correlation between resolution of fatty liver and risk of development of incident diabetes. In fact, after correcting for BMI, age, sex, physical activity, and other factors, the researchers noted, “In these individuals, there was no increase in risk of incident diabetes over that period, and risk of incident diabetes was similar to that observed in people who did not have fatty liver (at either baseline or follow-up examination).”

However, the subjects who developed new NAFLD at follow-up showed an increase in risk for incident diabetes, while patients whose fatty liver progressed from mild to moderate or severe exhibited a “marked” increase in risk for incident diabetes, most likely due to “changes in visceral adiposity, lifestyle (physical activity, alcohol, smoking), insulin sensitivity, or lipids,” or even a liver-specific effect such as the secretion of inflammatory cytokines.

The scientists concluded, “With the caveat that this study design cannot address causal relationships, these data strongly suggest that NAFLD severity is associated with a greater risk of diabetes, and attenuation of fatty liver status decreases risk of developing diabetes.”
— Derek Bagley

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