Exclusive human milk diets may overcome programming for the metabolic syndrome

Exclusive human milk diets may overcome programming for the metabolic syndrome

The metabolic syndrome describes the development as an adult of centripetal obesity, high blood pressure, high triglycerides, elevated blood sugar and low HDL cholesterol. These constellation of problems significantly increase the risk of cardiovascular disease, stroke and diabetes.

The origins of this syndrome may begin in the newborn period as previous research has noted an association with infants who are born SGA and development of insulin resistance later in life as in the paper Insulin resistance in young adults born small for gestational age (SGA). A relationship to the metabolic syndrome has been also noted in the paper Small for gestational age and obesity related comorbidities.

The theory here is that conditions in utero in which the fetus is chronically deprived of blood flow and nutrition lead to a tendency towards insulin resistance. The body is essentially trying to use any energy it is receiving to stay alive in an environment in which resources are scarce. Given that situation, resisting the effects of insulin by preventing storage of this needed energy serves a useful purpose but in the long run may be detrimental as the body become programmed to resist the effects of this hormone.

What if this programming could be overcome?

Breast milk certainly has many incredible properties and as we learn more we discover only more applications.  My previous post on putting breast milk in the nasal cavity is just one such example (Can intranasal application of breastmilk cure severe IVH?).  In 2019 Dr. Hair and Abram’s group looked at this with respect to insulin resistance and with potential extrapolation to the metabolic syndrome in their paper Premature small for gestational age infants fed an exclusive human milk-based diet achieve catch-up growth without metabolic consequences at 2 years of age. Texas Children’s Hospital uses an exclusive human milk diet for premature infants with the following criteria GA of <37 weeks, BW of ≤1250 g, with the diet maintained until approximately 34 weeks PMA.  Exclusive human milk is provided through a combination of mother’s own milk and Prolacta instead of a bovine based human milk fortifier.  In this study they were able to prospectively track 51 preterm infants of which 33 were AGA and 18 SGA.  The first visit (visit 1) was performed at 12–15 months CGA and the second visit (visit 2) was at 18–22 months CGA.  The question at hand was whether these children would experience catch up growth at 2 years of age and secondly what their levels of insulin might look like at these times.  Higher insulin levels might correlate with levels of insulin resistance with higher levels being needed to maintain euglycemia.  As a measure of insuline resistance the authors used the calculation of the Non-fasting homeostatic model of assessment-insulin resistance (HOMA-IR) =  (insulin × glucose)/22.5 which has been validated elsewhere. Protein intakes were equal for both groups at about 4 g/kg of human milk protein.

The Results Please

The SGA group had greater weight gain between visit 1 and 2 as evidenced by a significant difference in the change in BMI z-score, AGA −0.21±0.84  vs.SGA 0.25±1.10.  I suppose this isn’t too shocking as we know that many babies born SGA experience catch up growth after discharge.  What is surprising and once again speaks to the power of breast milk  is the impact observed on insulin levels and resistance to the same as measured by the HOMA-IR (AGA babies are the left column and SGA the right).

The adjusted p vlaues for glucose were 0.06 with insulin and HOMA-IR being 0.02.  What does this mean?  Well, these are not fasting insulin levels which would be ideal but what it does say is that at fairly comparable glucose levels the level of insulin is higher in former AGA babies and the level of insulin resistance lower in the SGA infants!  This result is quite the opposite of what previous studies have shown as referenced above.  Aren’t these growth restricted infants supposed to have had insulin resistance in utero and been programmed for life to have insulin resistance and as adults develop the metabolic syndrome?  This study falls short of making any claims about the latter as these infants are only two years of age.  What this study provides though is certainly a raised eyebrow.  There will be those of course that look at the size of the study and dismiss it as being too small but at the very least this study will lead to further work in this area.  This paper though adds to the mystery around the potential impacts of breast milk and certainly provides strength to the thought that perhaps breastmilk should be the exclusive source of nutrition for preterm infants in the NICU.  While I understand that not all women are able to produce enough for their own infants or may choose not to for a variety of reasons, with access to donor milk supply this could become a reality.  The cost savings to the health care system by preventing insulin resistance would be many fold greater than the cost of donor milk in the newborn period.

Another intriguing question will be whether use of an exclusive human milk diet with use of only mother’s own milk will have similar effects or even greater impact on glucose homestasis later in life.  I think the authors are to be commended for their dedication to work in this field and I certainly look forward to the next publication from this group.

 

Can we reduce severe IVH with elevated midline head positioning for ELBWs?

Can we reduce severe IVH with elevated midline head positioning for ELBWs?

Recently the practice of keeping ELBW infants with a midline head position for the first three days of life has been recommended to reduce IVH as part of a bundle in many units.  The evidence that this helps to reduce IVH has been somewhat circumstantial thus far.  Studies finding that decreased sagittal sinus blood flow, increased cerebral blood volume with increased intracranial pressure all occur after head turns would theoretically increase the risk of IVH.  Raising the head of the bed would help in theory with drainage of the venous blood from the head  and in fact systemic oxygenation has been shown to improve with such positioning.  This presumably is related to increased cardiac output from better systemic venous return.

Bringing it to the bedside

Interestingly, some of the above studies are from over thirty years ago.  We now have some evidence to look at involving this practice.  Kochan M et al published Elevated midline head positioning of extremely low birth weight infants: effects on cardiopulmonary function and the incidence of
periventricular-intraventricular. The study involved maintaining ELBW infants in an elevated midline head position (ELEV- supine, head of bed elevated 30 degrees, head kept in midline) versus standard head positioning (FLAT–flat supine, head turned 180 degrees every 4 h) during the first 4 days of life to see if this would decrease in the incidence of IVH. Ninety infants were randomized into both arms of the study.  In terms of baseline characteristics, BW of 725g in the FLAT vs 739 in ELEV were comparable as well as GA both at 25 weeks. Two differences on the maternal side existed of 40% ELEV vs 24.4% FLAT of mothers having preeclampsia and 23.3% FLAT vs 10% ELEV having prolonged rupture of membranes both of which were statistically significant.

What did they find?

Ultrasounds were performed at entry into the study and then daily for days 1-4 and then on day 7 with abnormal scans repeated weekly.  In terms of IVH the authors noted no overall difference in rate of IVH.  What they did find however was a statistically significant reduction in the rate of Grade IV IVH.  The p value for the finding of lower rates of Grade IV IVH was 0.036 so not strikingly significant but different nonetheless.  Given that the venous drainage of the head is also dependent on the resistance to flow from the pressure in the thorax one can’t infer that the intervention alone is responsible for this without ensuring that that respiratory findings are similar as well.  Similarly without knowing inflow of blood into the head as measured by blood pressure it is difficult to say that the reduction in IVH isn’t related to differences in blood pressure.

The authors helpfully looked at both of these things.  For those infants on high frequency ventilation the mean airway pressure was higher on day one being 11.5 cm H2O (FLAT) vs 9.9 cm H2O (ELEV) neither of which are high although different.  The rest of the three days were no different.  For those on conventional ventilation the only difference was on day 4 where the MAP was higher for ELEV at 8 vs 7.4 cm H2O which again is fairly mild. Interestingly, as was found in other studies that oxygenation was improved with elevation of the head, the maximum FiO2 for the two groups was different on day 1 being 46% in the FLAT vs 37.5% in the ELEV.

Looking at the hemodynamic side of things there were differences in the lowest mean BP recorded on day 1 and 3 but otherwise the groups were similar. It would have been nice to see mean results during this time rather than lowest but this is what we have.

In terms of complications of preterm birth there were no differences found in rates of sepsis (important given the increase rate of prolonged rupture in the FLAT group), NEC or ROP.

Although length of stay was no different 92 vs 109 days ELEV (NS), survival to discharge was at 88% vs 76% (p=0.033) which also may explain the longer length of stay.

What Can We Learn From This

Don’t worry.  I am not about to throw the results out.  There are a couple observations though that need to be addressed.  The first is the increased rate of preecampsia in the ELEV group.  This finding could have impacted the results.  We know that fetuses exposed to this condition are stressed and are often born with better lungs than their non-exposed counterparts.  The endogenous increase in steroids due to this stress is attributable and may explain the better oxygenation and lower mean airway pressures needed in the ELEV group rather than improvements in flow alone from positioning.  The second issue is adherence to the protocol as there were some infants in the ELEV group who were placed flat for the final 1-2 days of the study.  Having said that, this would serve to dilute the effect rather than strengthen it so perhaps it makes the results more believable.

So where does this leave us?  This study demonstrates improved survival and a reduction in Grade IV IVH without an overall reduction in IVH.  There was nothing found to suggest that the intervention is harmful.  Given the background studies demonstrating improved systemic oxygenation, reductions in ICP and cerebral blood volume the finding of reduced severe IVH seems plausible to me. This could be a practice changing study for some units who have perhaps only adopted midline positioning in the first few days of life.  It will be interesting to see if this takes off but is certainly worth a good look at.

Intratracheal instillation of steroids to prevent BPD

Intratracheal instillation of steroids to prevent BPD

Choosing to provide postnatal systemic steroids to preterm infants for treatment of evolving BPD has given many to pause before choosing to administer them. Ever since K Barrington published his systematic review The adverse neuro-developmental effects of postnatal steroids in the preterm infant: a systematic review of RCTs. and found a 186% increase in risk of CP among those who received these treatments, efforts have been made to minimize risk when these are given.  Such efforts have included shortening the exposure from the length 42 day courses and also decreasing the cumulative dose of dexamethasone.  Fortunately these efforts have led to findings that these two approaches have not been associated with adverse neurodevelopmental outcomes.  Having said that, I doubt there is a Neonatologist that still doesn’t at least think about long term outcome when deciding to give dexamethasone.  The systemic application certainly will have effects on the lung but the circulating steroid in the brain is what occupies our thoughts.

What About Applying it Directly to the Lung

If you wanted to prevent BPD the way to do it would be to minimize the time infants are exposed to positive pressure ventilation.  Rather than giving steroids after a week or two maybe it would be best to give them early.  Recent evidence supports this for systemic steroids and has been written about recently. Hydrocortisone after birth may benefit the smallest preemies the most! This still involves providing steroid systemically.  Over the years, inhaled steroids have been tried as have intratracheal instillation of steroid with and without surfactant as a vehicle for distribution to the lung.  This month colleagues of mine anchored by Dr. G. t’Jong (a founding member of the “Tall Men of Pediatrics #TMOP) published a systematic review and meta-analysis of all such RCTs in their paper Efficacy and safety of pulmonary application of corticosteroids in preterm infants with respiratory distress syndrome: a systematic review and metaanalysis.  The results of the study suggest that there may well be a role for this approach.

All of the included studies used a prophylactic approach of giving between the first 4 hours and the 14th day of postnatal age doses of pulmonary steroids with the goal of preventing death or BPD. The GA of enrolled infants ranged from 26 to 34 weeks, and the birth weight ranged from 801 to 1591 g. Out of 870 possible articles only 12 made the cut and compromised the data for the analysis.

Routes of steroid were by inhalation, liquid instillation though the endotracheal tube or by mixing in surfactant and administering through the ETT.

What Did They Find?

Using 36 weeks corrected age as a time point for BPD or death, the forrest plot demonstrated the following.  A reduction in risk of BPD or death of 15% with a range of 24% to only a 4% reduction.

Looking at the method of administration though is where I find things get particularly interesting.

What this demonstrates is that how you give the steroids matters.  If you use the inhalational or intratracheal instillation (without a vehicle to distribute the steroids) there is no benefit in reduction of BPD or death.  If however you use a vehicle (in both Yeh studies it was surfactant) you find a significant reduction in this outcome.  In fact if you just look at the studies by Yeh the reduction is 36% (CI 34 – 47%).  In terms of reduction of risk these are big numbers.  So big one needs to question if the numbers are real in the long run.

Why might this work though?

In the larger study by Yeh, budesonide was mixed with surfactant and delivered to intubated infants every 8 hours until FiO2 was less than 30%, they were extubated or a maximum of 6 doses were reached.  We know that surfactant spreads throughout the lung very nicely so it stands to reason that the budesonide could have been delivered evenly throughout the lung.  Compare this with inhalational steroid that most likely winds up on the plastic tubing or proximal airway.  The anti-inflammatory nature of steroids should decrease damage in the distal airways offsetting the effects of positive pressure ventilation.

Future Directions

I am excited by these findings (if you couldn’t tell).  What we don’t know though is whether the belief that the steroid stays in the lung is true. Are we just making ourselves feel better by believing that the steroid won’t be absorbed and move systemically.  This needs to be tested and I believe results of such testing will be along in the near future.

Secondly, we need a bigger study or at least another to add to the body of research being done.  Such a study will also need long term follow-up to determine if this strategy does at least have equal neurodevelopmental outcomes to the children who don’t receive steroid.  The meta-analysis above does show in a handful of studies that long term outcome was no different but given the history of steroids here I suspect we will need exceptionally strong evidence to see this practice go mainstream.

What I do believe is whether you choose to use steroids prophylactically using hydrocortisone or using intratracheal surfactant delivered budesonide, we will see one or both of these strategies eventually utilized in NICUs before long.

 

Keeping up with the Kardashians: Should you eat your placenta after delivery?

Keeping up with the Kardashians: Should you eat your placenta after delivery?

The medical term for this is placentophagy and it is a real thing. If you follow the lay press you may have seen that originally this was promoted by Kourtney Kardashian who did this herself and then by Kim who planned on doing the same after delivery. See Did Kourtney Kardashian Eat Her Placenta?

This is not completely without basis as many readers will be thinking already that they have heard about the health benefits of doing the same. Reports of improved mood and reductions in the baby blues following ingestion of placenta as well as improvements in breast milk production have led to this growing practice. The evidence for this up until recently though was quite old and fraught with poorly design of such studies. The bigger driver however has been word of mouth as many women having heard about the promises of better mood at the very least have thought “why not? Can’t hurt.”

What I will do in this post is run through a little background and a few recent studies that have shed some light on how likely this is to actually work.

Where did the idea come from?

Animals eat their placentas after delivery. It turns out that unprocessed placenta is quite high in the hormone prolactin which is instrumental for breastfeeding. Given the large amount of this hormone as well as the number of other hormones present in such tissue it was thought that the same benefits would be found in humans. Eating unprocessed human tissue whether it is put in a capsule or not is unwise as unwanted bacteria can be consumed. In fact, a case of GBS sepsis has been linked to such a practice in which the source of the GBS was thought to be due to contaminated unprocessed maternal placenta that had been ingested. Buser GL, Mat´o S, Zhang AY, Metcalf BJ, Beall B, Thomas AR. Notes from the field: Late-onset infant group B streptococcus infection associated
with maternal consumption of capsules containing dehydrated placenta.

What happens when you process placenta by steaming and drying?

This would be the most common way of getting it into capsules. This process which renders it safe to consume may have significant effects on reducing hormonal levels.This was found in a recent study that measured oxytocin and human placental lactogen (both involved positively in lactation) and found reductions in both of 99.5% and 89.2%, respectively compared versus raw placenta. I would assume that other hormones would be similarly affected so how much prolactin might actually wind up in these capsules after all?

Clinical Randomized Double Blind Controlled Trial

Twenty seven women from Las Vegas were recruited into a pilot trial (12 beef placebo vs 15 steamed and dried placenta) with the authors examining three different outcomes across three studies. The first study Effects of placentophagy on maternal salivary hormones: A pilot trial, part 1 looked at a large number of salivary hormones at four time points. Plasma samples were taken as well to determine the volume of distribution of the same. First samples were at week 36 of gestation then within 4 days (96 h) of birth followed by days 5–7 (120–168 h) postpartum and finally Days 21–27 (504–648 h) postpartum. All consumption of capsules was done in the home as was collection of samples. As per the authors in terms of consumption it was as follows “two 550 mg capsules three times daily for the first 4 days; two 550 mg capsules twice daily on days 5 through 12, and then to decrease the dose to two 550 mg capsules once daily for the remainder of the study (days 13 through approximately day 20 of supplementation).

Outcomes

No difference was found between salivary concentrations of hormones at any time point other than that with time they declined following birth. Curiously the volume of distribution of the hormones in serum was slightly higher in the placenta capsule groups but not enough to influence the salivary concentrations. It was felt moreover that the amount of incremental hormone level found in the serum was unlikely to lead to any clinical response.

The second study was on mood Placentophagy’s effects on mood, bonding, and fatigue: A pilot trial, part 2. Overall there were no differences for the groups but they did find “some evidence of a decrease in depressive symptoms within the placenta group but not the placebo group, and reduced fatigue in placenta group participants at the end of the study compared to the placebo group.”

The last paper published from the same cohort is Ingestion of Steamed and Dehydrated Placenta Capsules Does Not Affect Postpartum Plasma Prolactin Levels or Neonatal Weight Gain: Results from a Randomized, Double-Bind, Placebo-Controlled Pilot Study. This study specifically addressed the issue of prolactin levels and found no difference between the groups. Neonatal weight gain was used as a proxy for breastmilk production as it was thought that if there was an effect on breastmilk you would see better weight gain. About 80% in both groups exclusively breastfed so the influence of formula one can’t take out of the equation. In the end weight gain was no different between groups although a trend to better weight gain was seen in the placebo group.

To eat or not to eat that is the question?

What is clear to me is that the answer to this question remains unclear! What is clear is that I don’t think it is wise to consume raw placenta due to the risks of bacterial contamination. Secondly, the levels of hormones left in the placental preparation and the most common preparation of steaming and drying leave hormone levels that are unlikely to influence much at all from a biochemical standpoint. It also seems that breastmilk production and neonatal weight gain aren’t influenced much by consumption of these pills.
The issue though in all of this is that while the previous research was of low quality, the current research while of better quality is at a low volume. These were pilot trials and not powered to find a difference likely. The finding in the subgroup of some effect on mood at the end of the study does leave some hope to those that believe in the power of the placenta to help. Would a larger study find benefit to this practice? My suspicion from a biochemical standpoint is not but that one may feel a benefit from a placebo response.
Should you go out and have your placenta prepared for consumption? If you have Kardashian like wealth then go for it if you think it will help. If you don’t then I would suggest waiting for something more definitive before spending your money on placentophagy.

Is Prophylactic Hydrocortisone The Magic Bullet For BPD?

Is Prophylactic Hydrocortisone The Magic Bullet For BPD?

I feel like this has been a story in the making for some time. Next to caffeine, the story of prophylactic hydrocortisone must be one of my more popular topics and has been covered more than once before as in A Shocking Change in Position. Postnatal steroids for ALL microprems or Early Hydrocortisone: Short term gain without long term pain. and the last post Hydrocortisone after birth may benefit the smallest preemies the most!  After reporting on this topic about once a year, a recent paper may wrap it all up in a bow for the holidays and present to us the conclusion after all this work on the topic.  I was extremely interested in this topic not just because I believe this therapy may have a future in the standard approach to neonatal care for VLBWs but because I have served on the CPS Fetus and Newborn committee with two of the authors of the paper.  Dr. Lacaze and Dr. Watterberg have an exceptional understanding of this topic and so when they band together with other experts in the field I take notice.  In fact here I am with Dr. Lacaze in case you doubted our history together (we also worked in Edmonton together but that is another story).

An Individual Patient Data Meta-Analysis

If you have read my previous posts then you know the story of why hydrocortisone given over the first 10-12 days of life might help those born before 30 weeks or < 1250g.  In essence the concept is that it has been shown previously that many infants with relative adrenal insufficiency may go on to develop BPD.  If you treat all such infants at risk you could theoretically reduce BPD.  Typically after a few studies examining a similar topic come out, one can combine them in a meta-analysis using aggregate data (averages of effect sizes for the individual studies) and see what the larger sample shows.  Another way to do it though is to go back to the original data and examine the infants at a more granular level allowing a greater identification and control of variables that might influence outcomes.  This is what the authors led my Michele Shaffer did here in the paper Effect of Prophylaxis for Early Adrenal Insufficiency Using Low-Dose Hydrocortisone in Very Preterm Infants: An Individual Patient Data Meta-Analysis.  There were a total of 5 studies on this topic but one study of 40 patients no longer had individual data so was excluded from analysis leaving 4 to look at.  The details of the four studies are shown below.  You can see that the inclusion criteria differed slightly but in general these were all infants up to 27 – 29 completed weeks and 500 – 1250g maximum who were treated with regiments as shown in the table.

 

 

 

 

 

 

What were the results?

Treatment with early low-dose hydrocortisone was associated with greater odds of survival without BPD at 36 weeks PMA after adjustment for sex, gestational age, and antenatal steroid use (aOR, 1.45; 95% CI, 1.11-1.90; I 2 = 0%). Also found were lower individual odds of BPD (aOR, 0.73; 95% CI, 0.54-0.98; I 2 = 0%), but not with a significant decrease in death before 36 weeks PMA (aOR, 0.76; 95% CI, 0.54-1.07; I 2 = 0%). Importantly although death by 36 weeks was not different, a decrease in death before discharge (aOR, 0.70; 95% CI, 0.51-0.97; I 2 = 0%) was found.  Also noted and important was a reduction in medical treatment for PDA OR 0.72 (0.56-0.93)

All of these outcomes sound important but in a subgroup analysis other interesting findings emerged.

When dividing the patients into those less then 26 weeks and those at or greater than that gestational age, the benefits appear to be limited to those in the latter group.  Levels of significance are high once you reach that GA suggesting that issues affecting those at younger gestational ages are less amenable to treatment.  On the other hand one could say that the benefits seen at 26 – 29 weeks GA are relatively strong using a glass is half full approach.  An important outcome worth noting is that while spontaneous intestinal perforation is noted to be a risk with prophylactic hydrocortisone, when you remove indomethacin from the equation the risk disappears.  For those units using prophylactic hydrocortisone one would likely need to choose between the two but if you are like our unit where we don’t have that option this may be one strategy to consider.

In terms of risk to giving such therapy the big one noted in the paper was an increase in risk for late onset sepsis.  Interestingly, this was limited though to the group under 26 weeks GA.  In essence then the messaging would appear to be that under 26 weeks there may be less benefit to such treatment and therefore the increased risk of late onset sepsis without such benefits on BPD would suggest not using it in this GA group.

Where do we land then?

It would be easy to cast this aside I suppose as the group you are most worried about (22-25 weeks) doesn’t seem to really benefit but has a risk of late onset sepsis.  That leaves us though with the group from 26-29 weeks.  They do seem to benefit and may do so to a significant degree.  They do develop BPD and to be honest we don’t have much outside of trying our best to use gentle ventilation to ameliorate their course in hospital.  It is worth noting that the one group that does seem to show the greatest benefit are those exposed to chorioamnionitis.  It is this group in particular that may be the best target for this intervention and I gather this has been discussed at a recent EPIQ meeting.

If one says no to trying this approach then the question that needs to be asked is whether doing nothing for this group is better than supporting them with hydrocortisone?  If your centre’s rates of BPD are top notch then maybe you don’t want to add something in.  If not though maybe it is time to rock the boat and try something different.  Makes me think of the following saying and might be something to think about.