Diabetes'increases birth defect risk'

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Created on Wednesday, 30 May 2012 00:00

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Diabetes'increases birth defect risk'

“Diabetic mothers-to-be have high risk of giving birth to children with congenital abnormality,” The Guardian said today.

The news is based on UK research that compared the rates of birth defects in women with and without diabetes. It found that about 7% of pregnancies in women with diabetes were affected by birth defects that were not caused by problems with the number or structure of the chromosomes. This was 3.8 times higher than the rate in women without diabetes. The study also found that women who have worse control over their blood sugar around the time of conception were at greater risk.

It has been known for some time that diabetes in pregnancy is associated with a higher risk of various complications, and this large study provides further evidence on the link between diabetes and birth defects. UK medical guidance already addresses this risk, and recommends that from adolescence onwards, women with diabetes should be routinely given information on the importance of planning any future pregnancies and on getting specialist care and advice when they decide to have a baby. Women with very poor control of their diabetes are also advised not to become pregnant until their blood sugar control has improved.

Women with diabetes are likely to already be aware of these risks. However, this study provides another reminder that diabetic women who are thinking about becoming pregnant should discuss their options with their doctor first.

Where did the story come from?

{sidebar id=11}The study was carried out by researchers from Newcastle University, the Regional Maternity Survey Office in Newcastle, and the South Tees NHS Trust. It was funded by Diabetes UK, the Department of Health, the Healthcare Quality Improvement Partnership, and the four primary care trusts in northeast England. The study was published in the peer-reviewed medical journal Diabetologica.

The Guardian provided good coverage of this story, and put it into context of what is already known about how a woman’s diabetes can affect her pregnancy. The shorter news article in The Independent covered the basics of the story, but could be taken to suggest that the study was the first to discover the risk. In fact, this risk has been known for some time.

What kind of research was this?

Pregnancies in women with diabetes are already known to be at increased risk of various complications, including stillbirth and birth abnormalities. This cohort study aimed to clarify the extent to which diabetes increases the risk of major birth defects, and how this risk is affected by other factors such as maternal age, smoking and socioeconomic status.

A cohort study is the best way to assess this type of question, which could not be answered by a randomised controlled trial. Clearly, women with diabetes differ from women without diabetes in terms of their medical condition, but the two groups may also vary in other ways. It is important that researchers take such differences into account during their analyses.

What did the research involve?

The researchers used data collected on approximately 401,000 pregnancies that occurred between 1996 and 2008. They looked at whether mothers had diabetes, and if their babies had birth defects. The researchers then looked at whether birth defects were more common in babies born to mothers with diabetes.

The researchers obtained their data from the north of England, collected by the Northern Diabetes in Pregnancy Survey (NorDIP) and the Northern Congenital Abnormality Survey (NorCAS). NorDIP contains data on pregnancies in women diagnosed with diabetes at least six months before conception. It does not include women with gestational diabetes (diabetes that only occurs in pregnancy).

The study excluded multiple pregnancies (twins or triplets) and included pregnancies where the baby died at or before 20 weeks of pregnancy, or where the pregnancy was terminated due to a foetal abnormality. It included all eligible births in the study region in the study period. Abnormalities were classified according to standard definitions, and could be recorded up to the age of 12 years. Some birth abnormalities are caused by problems with the number or structure of chromosomes (the structures in the cell that contain our DNA). These abnormalities were looked at separately.

The researchers looked at the effect of various diabetes-related factors including how well the woman’s blood sugar was controlled at around the time of conception, whether she had type 1 or type 2 diabetes, and diabetes complications diagnosed before pregnancy (such as kidney or eye problems). They also looked at the effect of maternal age at the time of delivery, gestational age at time of delivery, folic acid intake before conception, foetal gender, number of previous babies, pre-pregnancy care, and smoking during pregnancy. Any significant factors were taken into account in the analyses to determine the effect of the individual factors.

What were the basic results?

Among the 401,149 pregnancies, 1,677 were in women with pre-existing diabetes. Most of these women (78.4%) had type 1 diabetes. Overall, 9,488 pregnancies were affected by at least one major birth defect, and 129 of these were in women with diabetes.

In women with diabetes, 71.6 per 1,000 pregnancies were affected by non-chromosomal major birth defects. This was 3.8 times higher than the rate in women without diabetes. Women with diabetes did not have an increased risk of having a baby with birth defects caused by chromosomal abnormalities.

When looking at specific factors linked to the risk of birth defects, the researchers found that women who had worse blood sugar control at around the time of conception were at increased risk of having babies with birth defects. Blood sugar control is often calculated using a measure called HbA1c level. This represents the levels of haemoglobin in the blood with a sugar molecule attached.

Doctors generally try to keep HbA1c levels below 7%. In this study, each increase of 1% in HbA1c over 6.3% was associated with a 30% increase in the odds of birth defects (odds ratio [OR] 1.3, 95% confidence interval [CI] 1.2 to 1.4). Women who already had kidney problems as a result of their diabetes also had an increased risk of having babies with birth defects (OR 2.5, 95% CI 1.1 to 5.3).

Some other factors were associated with an increased risk of birth abnormalities when looked at in isolation, such as low intake of folic acid and lower socioeconomic status. However, once all other factors were taken into account, these were no longer statistically significant.

How did the researchers interpret the results?

The researchers concluded that the main modifiable factor associated with birth defects in women with diabetes is their blood sugar control at around the time of conception. They say that the association with diabetes-related kidney problems needs to be studied further.

Conclusion

This study supports the existence of an association between maternal diabetes and increased risk of birth abnormalities, and helps quantify the size of the association. The study’s strengths include its large size and ability to include the entire population in the study area. However, there are a number of points to note:

The researchers took into account various factors that could influence the results. However, as with all studies of this type, it is possible that unknown or unmeasured factors, other than maternal diabetes, could have affected the risk of birth defects.

From this study we cannot say what effect diabetes arising in pregnancy (gestational diabetes) might have on risk of birth defects, as these women were not included in this analysis.

The study relied on registry-recorded data, and there may be some omissions or inaccuracies in this data. That said, the registries used standard systems for recording data that should increase the reliability of their records.

The link between maternal diabetes and an increased risk of birth defects is already established. Better blood sugar control can help reduce this risk, although it cannot eliminate the risk completely. The National Institute for Health and Clinical Excellence (NICE) recommends that women with diabetes who are trying to conceive should aim for an HbA1c of less than 6.1%, if this can be achieved safely. It also suggests that women with an HbA1c of over 10% should avoid becoming pregnant.

NICE also recommends that:

Women with diabetes who are planning to become pregnant should be informed of the need to establish good blood sugar control before conception, and that maintaining it throughout pregnancy will reduce the risk of miscarriage, birth defects, stillbirth and neonatal death. They also say that it is important for healthcare providers to explain that these risks can be reduced, but not eliminated entirely.

The importance of avoiding unplanned pregnancy should be an essential component of diabetes education from adolescence onwards for women with diabetes.

Women with diabetes who are planning to become pregnant should be offered pre-conception care and advice before they stop using contraception.

This study supports the need for specialist information and planning for pregnancy in women with diabetes. Women with diabetes who are thinking about becoming pregnant should discuss this with their doctor if they have not already done so.

Source: NHS UK, 02 February 2012

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Kotoko crowned Ghana champions

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Category: Sports & Entertainment

Created on Sunday, 27 May 2012 00:00

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Kotoko crowned Ghana champions

A spectacular end to an intriguing season as Asante Kotoko are crowned champions of the Ghana Premier League.

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'Crash diets' studied for type 2 diabete

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Created on Tuesday, 29 May 2012 00:00

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'Crash diets' studied for type 2 diabete “A crash diet could end the misery of type 2 diabetes for millions of sufferers,” reported the Daily Mirror. It said a study has found that a “special 600-calories-a-day eating plan cuts fat in the pancreas and prompts insulin cells to wake up after just eight weeks”. Many newspapers covered this study, and most claimed that it has found a “cure”. However, this was a very small, preliminary study in only 11 obese people with type 2 diabetes. Referring to this diet as a cure exaggerates the significance of the findings. {sidebar id=11}The study tested the theory that severely restricting the amount of energy in the diet can reverse the body’s resistance to insulin, which occurs in type 2 diabetes, and halt the progressive decline in function of pancreas cells that produce insulin. Very limited conclusions can be drawn from the study’s findings, and much further research is required. Alone, this study provides no evidence of a cure for diabetes. People with type 2 diabetes should continue to follow the dietary advice given to them by their doctor. The participants in this study were all given medical supervision throughout, and people with the condition are advised not to try this diet on their own. Where did the story come from? The study was carried out by researchers from the Human Nutrition Research Centre at Newcastle University. Fundjng was provided by Diabetes UK. The study was published in the peer-reviewed medical journal Diabetologia. Many of the news stories have exaggerated the implications from the findings of this very small, preliminary study. What kind of research was this? This research investigated whether an energy-restricted diet had an effect on the biochemical signs of type 2 diabetes in people with the condition. Type 2 diabetes occurs when not enough insulin is produced by the pancreas for the body to function properly, or when the body’s cells do not react to insulin. Insulin is a hormone that helps the body use glucose for energy. The condition is progressive as the increased demand on the pancreas to create more insulin leads to further decline in function of the insulin-producing beta cells. Many people who have type 2 diabetes for a long time have to start injecting insulin as their condition worsens. The researchers wanted to see whether their diet could reverse the resistance of the body’s cells to the actions of insulin, and prevent progressive decline in function of beta cells. This research was a non-randomised, study in 11 people with type 2 diabetes. For comparison, the researchers also conducted one-off measurements in nine people without diabetes who did not receive the dietary intervention. However, this was not a controlled study as there was no comparison group of people with diabetes who received a comparison intervention (such as an alternative diet) or no dietary intervention. The researchers say that previous studies have found that weight-loss surgery can help reverse diabetes. This gave them the idea that a sudden negative energy balance, taking in fewer calories than the body burns, could have a profound effect on metabolism (the rate at which the body turns food into energy). Excess concentrations of fatty acids are also said to inhibit the function of beta cells, so it was expected that a decrease in fatty acid levels would improve the function of these cells. What did the research involve? The researchers recruited 15 people with type 2 diabetes. Their average age was 49.5 and they had an average body mass index (BMI) of 33.6 (which is classed as obese). The participants had had type 2 diabetes for less than four years. In the weeks leading up to the study, their diabetic medications (metformin in seven people and sulfonylurea in two) were withdrawn. Eleven people with diabetes and eight without the condition completed the study, and the researchers reported the findings for these people only. Laboratory methods were used to assess insulin sensitivity of the liver and other body tissues at the start of the study, in addition to the level of glucose output from the liver. A special type of MRI scan was used to measure the fatty acid (triacylglycerol) content of the liver and pancreas. The people then began a diet of nutrient drinks (46.4% carbohydrate, 32.5% protein and 20.1% fat, plus vitamins, minerals and trace elements), which supplied 510 calories a day (kcal/day). This was supplemented by three portions of non-starchy vegetables to give a total energy intake of 600 kcal/day. Further measurements were taken at one, four and eight weeks after starting the diet. At eight weeks, the participants returned to normal eating, but MRI scans were carried out again at 12 weeks. The comparison group of nine people without diabetes were matched to the people with diabetes in terms of their age, sex and weight. One-off measurements were taken from these people at the beginning of the study. These people received no dietary intervention. What were the basic results? After one week of the restricted-energy diet, fasting plasma glucose (blood sugar levels) normalised (decreasing from an average of 9.2 to 5.9 millimoles per litre). The production of glucose from the liver also decreased, and the liver’s sensitivity to insulin improved from 43% at the beginning of the study to 74% after one week. By week eight, the fatty acid content of the liver had fallen from 12.8% at the study’s start to 2.9%, while levels in the pancreas fell from 8.0% to 6.2%. The sensitivity of pancreatic cells to glucose improved over the eight weeks of the intervention. The researchers did not notice a change in the insulin sensitivity of other body tissues apart from the liver. Over the eight weeks of the diet, the average weight loss was 15.3kg (equivalent to 15% of the participants’ initial bodyweight). By 12 weeks (four weeks after the diet was stopped), participants had gained an average 3.1kg in weight. Decreases in triacylglycerol content of the liver and pancreas were maintained after the participants came off the diet, but fasting blood sugar increased. How did the researchers interpret the results? The researchers concluded that a restricted-energy diet brought the function of pancreatic beta cells back to normal and improved the sensitivity of the liver to insulin in people with type 2 diabetes. The amount of fat stored in the pancreas and liver also decreased. Conclusion This was a very small preliminary, non-randomised, uncontrolled study. Only 11 people with diabetes received the dietary intervention. Although the researchers took one-off measures in eight people without diabetes for comparison, these people did not follow the diet. There was also no comparison group of people with diabetes who did not receive the diet intervention. As such, very limited conclusions can be made from this study. Contrary to some news reports, it provides no evidence of a cure for diabetes. Importantly, the study only examined the effects of eight weeks of an extreme energy-restriction diet, where the daily intake was only 600 calories. The longer-term health implications and risks of such a diet are not known. Carefully conducted randomised controlled dietary studies in a much larger number of people with type 2 diabetes, and with longer follow-up, are needed. This research will need to carry out a more detailed assessment of the possible effects of such an intervention on diabetic control and on health in general. It will also need to ascertain whether the positive effects seen in this study are sustained when a person returns to a normal diet. People with type 2 diabetes should continue to follow the dietary advice given to them by their doctor. The participants in this study were all given medical supervision throughout, and it is advised that people with the condition do not attempt this diet on their own. Source: NHS UK, 06 June 2011

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Fatty food 'trigger' for diabetes

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Created on Friday, 25 May 2012 00:00

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Fatty food 'trigger' for diabetes

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