January 2, 2013
Preeclampsia is a potentially dangerous condition during pregnancy that can lead to life-threatening high blood pressure, kidney failure, and fetal growth delay. Dr. Colin Sullivan (the inventor of the CPAP machine) has published a series of studies on the beneficial effects of using CPAP to control preeclampsia. In his latest study, he and his colleagues showed that fetal movements were significantly lower in mothers with preeclampsia compares to controls. Using CPAP at relatively low pressures significantly increased the number of fetal movements. Over the course of the night, women not on CPAP had progressively lower fetal movements, whereas those on CPAP had progressively increased fetal movements.
Just like in their previous studies, many of these women had only mild obstructive sleep apnea. Some did not have sleep apnea at all. However, the vast majority had what’s called inspiratory flow limitation, where there is partial obstruction to inhalation, but not meeting the criteria for an apneas (10 second pauses and/or lowered oxygen levels).
It’s likely that they are treating is upper airway resistance syndrome, with multiple partial obstructions and arousals that don’t present as classic obstructive sleep apnea.
It’s disappointing that despite this important information about pre-eclampsia, there’s been no significant movement to look for sleep-related breathing disorders in preeclamptic women.
If you ever had preeclampsia during pregnancy, did your doctor ever ask about your snoring or sleep quality?
May 28, 2012
Having high blood pressure during pregnancy (also called preeclampsia) was found to increase the offspring’s risk of having high blood pressure in childhood and young adulthood. This study published in Pediatrics analyzed 18 studies and looked at cardiovascular risk factors in people exposed to high blood pressure during pregnancy. Those that were exposed had a systolic blood pressure that was 2.39 mm Hg higher compared to those whose mothers had healthy pregnancies. The diastolic pressure was 1.35 mm Hg higher. They calculated that over time, these figures would increase one’s risk for dying from heart disease by 8% and from stroke by 12%.
What’s my take on this study? It’s not surprising, since many women with preeclampsia have sleep-breathing problems such as obstructive sleep apnea and upper airway resistance syndrome. It’s been shown that treating with CPAP can lower blood pressure in women with preeclampsia. Despite this knowledge , sleep apnea is almost never considered when treating preeclamptic women in the US. Having hypoxia and physiologic stress from the mother’s poor sleep quality can be detrimental to the developing fetus. Since the offspring will also inherit the mother’s upper airway anatomy, it’s not surprising that the child will be predisposed to the consequences of obstructive sleep apnea, such as high blood pressure, diabetes, heart attack and stroke. It’s also likely that environmental and dietary factors during pregnancy may carry over into the household which can also affect the child’s diet.
May 7, 2012
Here’s a not-to-surprising study showing that obese women are at higher risk of having children with autism. Obese women were 67% more likely to have an autistic child, and about 2x as likely to have an child with another developmental disorder. Having gestational diabetes also raised by 2x a mother’s risk of having a baby with developmental disorders.
They also note that nearly 60% of women of childbearing age in the US is overweight and about 1/3 are obese. Obesity rates are rapidly climbing. Autism rates are also climbing, with the latest report showing 1/88 children having one of the autism spectrum disorders.
The authors mentioned every possible explanation (diabetes, high blood pressure, fluctuating glucose levels, lack of oxygen) expect for obstructive sleep apnea. I’ve written numerous times in the past about complications of obstructive sleep apnea during pregnancy. If you’re overweight or obese, you’re much more likely to have obstructive sleep apnea. One of the hallmarks of sleep apnea is hypoxia and major physiologic stress on the mother’s body. I wonder what the effect is on the developing baby’s brain? It would make sense to routinely screen for sleep apnea in all women, especially if you’re overweight or heavier.
If you were overweight during pregnancy, did your doctor screen you for obstructive sleep apnea?
August 21, 2011
Having an asthma attack in the middle of the night can be a frightening and terrifying experience. Typically, these attacks happen in the early morning hours, just before awakening.
Now there’s research showing that poorly controlled asthma during pregnancy can increase a woman’s chances of developing preeclampsia (50%) and premature births (25%). Furthermore, infants born to mothers with poorly controlled asthma delivered babies that were about 0.2 pounds less than those born to mothers without asthma.
We typically think of asthma being a separate, distinct condition from obstructive sleep apnea, and it’s treated in completely different ways. However, it’s not just coincidence that nocturnal awakenings from asthma and the most intense periods of apnea occur at the same time in the middle of the night—the early morning hours. The early morning hours are when REM sleep is most prominent, and this is the time when throat muscles are most relaxed. Having an apnea also is known to cause reflex, which is known to reach the throat as well as the nose and the lungs. In one small study in people with sleep apnea and asthma, treating sleep apnea with CPAP significantly improved nocturnal asthma symptoms.
We know that any degree of stress on the mother’s body can lead to a higher rate of pregnancy-related complications and low birth rates. Even snoring by the mother alone was found to result in lower Apgar scores in newborn infants. Apneas are also known to raise blood pressure and promote insulin resistance. Stress hormones are also known to increase when you have apneas.
In light of all these findings, it’s not surprising that pregnant women with poorly controlled asthma have higher complications rates. This is another great example of “connecting the dots” between two seemingly unrelated conditions, which only adds to support my sleep-breathing paradigm.
August 3, 2011
As a follow-up to my post last week on why pregnant women may have an increased risk of stroke, here’s a study published this month in the journal Sleep. Researchers compared 34 women with gestational hypertension vs. 26 healthy women with uncomplicated pregnancies. Significant sleep-disordered breathing was defined as a respiratory disturbance index (RDI) of 5. Pregnant women with high blood pressure had significant sleep-disordered breathing in 53%, whereas 12% of healthy pregnant women had sleep-disordered breathing. Hypertension is a known risk factor for preeclampsia and stroke.
This study is in line with my suspicion that pregnant women, while at risk for obstructive sleep apnea, probably have shorter obstructions and RERAs (respiratory-effort related arousals), rather than frank apneas. Increased progesterone and various other physiologic changes seen in pregnancy can increase your respiratory drive and lower arousal thresholds, leading to more frequent arousals from deep sleep.
Notice how commonly pregnant women snore, and they’re extremely tired. If they weren’t pregnant, doctors would suspect obstructive sleep apnea. Then why do we have this double standard? Why can’t women who suddenly gain weight and snore be routinely screened for obstructive sleep apnea?
July 28, 2011
Rates of stroke went up 47% for expectant mothers and climbed to 83% in the first three months after delivery. This was the finding that was published in the journal Stroke: Journal of the American Heart Association. They cite rising rates of additional risk factors such as high blood pressure, obesity, and gestational diabetes, but didn’t give a plausible explanation. Here’s a story about this study published in the Wall Street Journal.
Here’s a simple explanation: Sleep-breathing problems. Whether it’s obstructive sleep apnea or more likely upper airway resistance syndrome, pregnant women tend to have more frequent breathing pauses, especially as they gain weight. One protective mechanism is through progesterone, which acts as a tongue muscle stimulant, but the forces of upper airway collapse is likely to overwhelm these protective effects. What’s even more striking is that the rate almost doubles immediately postpartum. Remember that progesterone drops soon after delivery, but you’re still left with all that additional weight. We know that obstructive sleep apnea can significantly increase your chances of stroke and heart attacks. There are even reports that suggest that preeclampsia can be successfully treated with CPAP.
Overall, the numbers are still very low, but the sudden rise in the rate of stroke in new mothers leaves researchers scratching their heads.
June 19, 2011
Researchers from New Zealand discovered that women who did not sleep on their left side the last night before delivering their babies had twice the rate of stillbirth compared with those that slept on their left side. It’s commonly recommended for pregnant women to sleep on their left side, especially later in pregnancy. There are various explanations for why this is preferred, from placing less pressure on the mother’s major blood vessels to worsening the mother’s snoring.
I’ve mentioned before that a woman’s risk of developing obstructive sleep apnea increases as she gains weight during pregnancy, but progesterone counteracts this effect neuromuscularly, by tensing the throat muscles and increasing the drive to breathe. However, back sleeping is a known aggravator of breathing pauses during sleep due to gravity’s effects on the tongue. Whether or not this leads to apneas (10 seconds or longer pauses), the mother will still stop breathing and wake up more often during the night. This can place a major stress not only on the mother’s body, but on the baby as well.
This study was an observational study, so more prospective studies are needed. But it only goes to show that any additional situation that can aggravate sleep-breathing problems during pregnancy can raise your risk of complications, which also includes gestational diabetes and preeclampsia.
I wonder if the researchers asked the women what their preferred pre-pregnancy sleep position was. I suspect that women who can’t sleep on their backs may have more complications during pregnancy due to narrowed upper airway anatomy.
April 8, 2011
A new study published this week in the Journal Human Reproduction found that obese pregnant women have a much higher chance of miscarriage or suffering from their child dying before the first birthday. Not too surprisingly, pre-eclampsia was the most common reason for these obesity-related deaths. Gestational diabetes increased as well.
We know that any significant weight gain can lead to obstructive sleep apnea. Then why is it that pregnant women don’t develop sleep apnea? One possible reason why this may not happen as often is that progesterone increases significantly during pregnancy. Progesterone is an upper airway muscle stimulant, increasing tongue muscle tone significantly. This is one way it protects against apnea-promoting effects of weight gain.
However, if you gain too much weight, or if there are other stresses in your life that hormonally diminishes the protective effects of progesterone, then you’ll have more problems breathing at night, leading to or aggravating various pregnancy complications. High blood pressure (seen in pre-eclampsia), and diabetes are more likely in people with sleep apnea.
What’s just as important is what happens after delivery: Progesterone drops, but you’re left with all that weight. By definition, your sleep quality will drop significantly. This is one mechanism that can aggravate post-partum depression. Imagine how much worse it may be if you also lose your child.
If you’re a woman and are overweight and have sleep apnea, did you suffer any miscarriages or pregnancy complications in the past?
February 18, 2011
February is American Heart Month, and one thing that’s being stressed more this year is the fact that many women’s heart problems go undiagnosed, especially if they have atypical symptoms. The American Heart Association just recently came out with revised guidelines of cardiovascular disease prevention for women. The two interesting points they make is that women have a higher proportion of strokes to heart attacks compared with men. The other point they at emphasize is the fact that if you had a complication during pregnancy, your risk of heart disease later in life is significantly higher.
What was surprising to me is that we have lots of studies showing that most cases of pregnancy-related complications such as preeclampsia and gestational diabetes may be caused by untreated obstructive sleep apnea. Since weight gain is a major risk for sleep apnea, why should pregnant women be excluded from having a sleep-breathing disorder? By definition, pregnancy will cause you to have temporary sleep-breathing problems, whether or not it’s officially obstructive sleep apnea.
The one thing that protects against sleep apnea during pregnancy is the rise in progesterone, which acts as an upper airway muscle stimulant, but this can only help so much. As progesterone drops after delivery, what do you think will happen to women who still have most their pregnancy weight? I’m willing to bet that if you do the same study looking at post-partum complications such as postpartum depression, you’ll see the same increased rate of heart disease later in life.
The shocking thing was that nowhere in these general guidelines do they even mention looking for obstructive sleep apnea. I won’t begin to talk about the link between stroke and sleep apnea–there are just too many studies to mention. I encourage you to take a look at the recommendations of the American Heart Association’s website. Tell me what you think about this glaring omission.
January 5, 2011
Believe it or not, your skin is considered an end organ, meaning that it’s at the outermost reaches of your blood supply. It’s also a part of your body which can be deprived of blood flow if you’re under stress, similar to what happens to your digestive or reproductive systems.
Psoriasis is a common skin condition that affects about 34 million Americans, or about 3% of the population. It’s characterized by red, scaly patches of skin covered by white flakes. It’s thought to be a chronic autoimmune condition, where your body’s immune system can attack or damage your own tissues.
I’ve written before about strong links between psoriasis and obstructive sleep apnea, but here are a series of studies that further solidifies this connection. Some of the studies I’ve cited before. Others are new:
Metabolic syndrome (Syndrome X) is a combination of high blood pressure, insulin resistance, and high cholesterol levels. Having all three conditions has been shown to significantly increase your risk of heart disease, heart attack, or stroke. Numerous studies show that people with metabolic syndrome can also have obstructive sleep apnea. In fact, syndrome Z has been described as all the features of Syndrome X plus obstructive sleep apnea.
A study published in Archives of Dermatology showed that patients with psoriasis had a higher chance of having metabolic syndrome compared to people who didn’t (40% vs. 23). I’ve written in the past about how chronic physiologic stress due to sleep apnea causes diversion of blood flow and nutrients to the bowels, reproductive organs, and the skin, since they’re considered “low priority” organs. Low blood flow causes a relative hypoxia, creating oxidative stress, and along with a heightened immune system, so it’s not surprising that the skin can show psoriatic plaques.
Here’s a study showed that women who drank more than two alcoholic beverages per week had a significantly higher risk of psoriasis. Alcohol relaxes your throat muscles, aggravating sleep apnea.
Researchers from harvard showed that comorbid conditions such as cardiovascular disease, depression, diabetes, obesity, and hyperlipidemia all increased over time. Not too surprising if you already have sleep apnea.
Pregnant women with psoriasis were found by Harvard and Mass General researchers to have higher risk of pregnancy-related complications, including spontaneous abortion, preterm birth, preeclampsia, placenta previa, and ectopic pregnancy. Gaining weight can aggravate sleep apnea. Studies show that CPAP can help with preeclampsia.
People with psoriasis were found to have increased risk of depression (39%), anxiety (31%) and suicidal thoughts (44%). Sleep apnea can cause structural, metabolic, and biochemical changes in your brain due to hypoxia.
And lastly, young adults who are obese were found to have a higher risk of developing psoriatic arthritis later in life. Obesity is a major risk factor for obstructive sleep apnea.
Perhaps psoriasis should be placed on the ever-growing list of complications of obstructive sleep apnea. What do you think?