Diet Soda Tied to Vascular Risk, With Caveats

By Todd Neale, Staff Writer, MedPage Today Published: February 09, 2011 Reviewed by Michael Mullen, MD; Clinical Instructor of Vascular Neurology, University of Pennsylvania.

 

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LOS ANGELES -- Drinking diet soda -- but not regular soda -- was associated with a greater risk of stroke, MI, or vascular death in an older, multiethnic cohort, researchers found. Individuals who reported drinking diet soda every day were 48% more likely to have a vascular event through more than nine years of follow-up (RR 1.48, 95% CI 1.3 to 2.12), according to Hannah Gardener, ScD, of the University of Miami in Florida.
There was no such association for less-frequent consumption of diet soda or for any level of regular soda consumption, she reported at the American Stroke Association's International Stroke Conference here.
In a separate study, Gardener and her research team also found that individuals who had the highest daily sodium consumption had a nearly threefold increased risk of stroke compared with those who met the American Heart Association target of 1,500 mg a day.
Gardener acknowledged some limitations of the diet soda study, including the use of self-reported dietary data at a single time point, and concluded that the findings are "too preliminary to suggest any dietary advice."
"If and only if the results are confirmed can we suggest that diet soda may not be an optimal substitute for sugar-sweetened beverages, which have been shown to have various health consequences," she said.
Doctors contacted by ABC News and MedPage Today were also hesitant to declare diet sodas the next great health risk, with many attributing the increased vascular risk to other dietary factors that were not measured in the study, such as the types of foods contributing to the total caloric intake.
"Unfortunately, it may be that individuals with poor dietary habits do resort [to] some kind of calorie balancing and continue to eat high-calorie sweet foods but reduce their 'guilt' by drinking diet soda," Howard Weintraub, MD, clinical director of the NYU Center for the Prevention of Cardiovascular Disease, wrote in an e-mail.
The study "adds to the growing evidence of an association between diet sodas and cardiovascular disease," according to Cam Patterson, MD, a cardiologist at the University of North Carolina at Chapel Hill. But, he added, that, although the association cannot be ignored, it is too early to interpret what it means.
"People need to know about this, but it is important for everyone to realize that no general guidelines should be derived from these types of observational studies," Patterson wrote in an e-mail.
"I'll continue to pack a diet soda with my lunch, but I'll look more carefully at what else is in my lunch box, and I'll pay more attention to what I'm doing while I'm drinking my diet soda."
Gardener and her colleagues analyzed data from the Northern Manhattan Study (NOMAS), which includes individuals older than 40 living in New York City.
The current analysis included 2,564 participants. Their mean age was 69; about half were Hispanic, one-fifth were white, and one-quarter were black.
Based on a food frequency questionnaire completed at baseline, 35% of the cohort did not drink either regular or diet soda. Only 24% reported drinking any amount of diet soda.
Diet soda consumption was associated with white race, diabetes, elevated blood sugar, low HDL cholesterol, elevated waist circumference and body mass index, peripheral vascular disease, and metabolic syndrome (P<0.05 for all).
Through an average follow-up of 9.3 years, there were 559 incident vascular events, including 212 strokes, 149 MIs, and 338 vascular deaths.
After adjustment for demographic and behavioral and vascular risk factors -- including BMI -- there was an increased risk of having a vascular event with daily diet soda consumption, but no other levels of consumption of diet or regular soda.
Commenting on the findings, Christopher Cannon, MD, of Brigham and Women's Hospital in Boston, pointed out, however, that the number of participants who drank diet soda daily was small -- 116 -- and that the lack of an association with regular soda consumption was at odds with previous studies.
"This suggests that the finding may be spurious, and needs confirmation in a much larger group of patients," he wrote in an e-mail.
Gardener agreed that confirmation was needed before drawing any definitive conclusions, with further studies that focus on a younger population with more diet soda consumption and that collect diet information at multiple time points.
She and her colleagues also examined the relationship between dietary sodium intake and stroke in the NOMAS cohort.
Although the American Heart Association recommends consuming less than 1,500 mg a day, only 12% of the participants met that goal.
The average daily consumption at baseline was 3,031 mg, with one-fifth of the cohort ingesting more than 4,000 mg a day.
Over a mean follow-up of 10 years, there were 227 strokes.
After adjustment for demographics and behavioral and vascular risk factors -- including hypertension -- every 500 mg/day increase in sodium intake was associated with an 18% relative increase in stroke risk (RR 1.18, 95% CI 1.08 to 1.27).
Those individuals who consumed the most -- more than 4,000 mg/day -- had a 2.67-fold (95% CI 1.31 to 5.41) increased risk compared with those who met the AHA target.
"The results of our study suggest that the new AHA strategic dietary goals will help promote ideal cardiovascular as well as brain health," Gardener said, "and this evidence can be used in campaigns aimed at reducing cardiovascular disease risk by targeting dietary behavior."

Early Introduction of Solid Foods Linked to Risk for Early Childhood Obesity

February 7, 2011 — Early introduction of solid foods is linked to a risk for early childhood obesity, according to the results of a prospective prebirth cohort study reported online February 7 in Pediatrics.
"Parental feeding practices during early infancy, such as the timing of solid food introduction, may be 1 key modifiable determinant of childhood obesity," write Susanna Y. Huh, MD, MPH, from the Division of Gastroenterology and Nutrition, Children's Hospital Boston in Boston, Massachusetts, and colleagues. "Data suggest that the introduction of solid foods earlier than 4 months of age is associated with increased body fat or weight in childhood or with greater weight gain during infancy, which itself predicts later adiposity. Other studies have found no association between the timing of solid food introduction and body fat or an association between delayed introduction of solid foods after 6 months and greater adiposity."
The goal of the study was to evaluate the association between timing of introduction of solid foods during infancy and obesity at age 3 years, defined as a body mass index for age and sex at the 95th percentile or above, using a cohort of 847 children enrolled in Project Viva. Timing of introduction of solid foods was categorized as younger than 4 months, ages 4 to 5 months, and 6 months or older. Logistic regression models were applied separately for infants who were breast-fed for at least 4 months ("breast-fed"; n = 568; 67%) and for infants who were never breast-fed or in whom breast-feeding was stopped before age 4 months ("formula-fed"; n = 279; 32%). These models were adjusted for child and maternal factors, including change in weight-for-age z score from 0 to 4 months as a marker of early infant growth.
Obesity was present in 75 children (9%) at age 3 years. The timing of solid food introduction was not associated with odds of obesity in breast-fed infants, (odds ratio, 1.1; 95% confidence interval [CI], 0.3 - 4.4). However, introducing formula-fed infants to solid foods before age 4 months was associated with a 6-fold increase in odds of obesity at age 3 years, which was not explained by rapid early growth (odds ratio after adjustment, 6.3; 95% CI, 2.3 - 6.9).
"Among infants who were never breastfed or those who stopped breastfeeding before the age of 4 months, the introduction of solids before the age of 4 months was associated with a sixfold increase in the odds of obesity at the age of 3 years," the study authors write.
Limitations of this study include possible residual confounding; some loss of the cohort to follow-up; limited generalizability to more socioeconomically disadvantaged populations; and small numbers in some cells, leading to possible chance results.
"Among infants breastfed for 4 months or longer, the timing of the introduction of solid foods was not associated with the odds of obesity," the study authors conclude. "Increased adherence to guidelines regarding the timing of solid food introduction may reduce the risk of obesity in childhood."
The National Institutes of Health supported this study. The study authors have disclosed no relevant financial relationships.

Pediatrics. Published online February 7, 2011. Abstract

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Authors and Disclosures

Journalist

Laurie Barclay, MD

Freelance writer and reviewer, Medscape, LLC

Disclosure: Laurie Barclay, MD, has disclosed no relevant financial relationships.

Phone App Improves Metabolic Control in Type 1 Diabetes

By Will Boggs MD

NEW YORK (Reuters Health) Feb 04 - Use of the Diabeo software on a mobile phone improves metabolic control in patients with chronic, poorly controlled type 1 diabetes, researchers from France report online in Diabetes Care.
An active electronic log book such the Diabeo system facilitates the management of complex insulin treatment of type 1 patients, improves blood glucose results and quality of life, and assists follow up by physicians "thanks to the transmission of whole data through GPRS (General Packet Radio System) and Internet," Dr. Guillaume Charpentier from Sud-Francilien Hospital, Corbeil-Essonnes, France told Reuters Health in an email.
Dr. Charpentier and colleagues evaluated the efficiency of the Diabeo system in improving metabolic control in a randomized, open-label, parallel-group study of 180 patients with chronic, poorly controlled type 1 diabetes. Voluntis, makers of Diabeo, provided the software, and sanofi-aventis partially funded the trial.
Diabeo software is uploaded onto smart phones with Internet connection that provides bolus calculators using validated algorithms; plasma glucose targets; automatic algorithms for adjusting carbohydrate ratio and basal insulin or pump basal rates; and data transmission to medical staff computers.
Mean HbA1c was 9.07% at baseline. At the end of the 6-month study, HbA1c was significantly lower in the 60 patients allocated to electronic logbook alone (8.63%) and in the 59 patients allocated to electronic logbook plus teleconsultation (8.41%) than in the 61 patients allocated to the usual paper logbook (9.10%).
Only the difference between the electronic logbook plus teleconsultation group and the usual paper logbook group remained statistically significant after adjustment for multiple comparisons.
Similarly, significantly more patients in the electronic logbook plus teleconsultation group (10/59, 17%) than in the paper logbook group (1/61, 1.6%) reached the target HbA1c of 7.5% or less, with patients in the electronic logbook only falling in-between (4/60, 6.7%).
The frequency of symptomatic, non-severe hypoglycemia didn't differ between groups and did not increase from baseline.
Also, quality of life at baseline and endpoint did not differ between the groups.
Total time spent on follow-up was the same among groups, but participants in the electronic logbook only and usual paper logbook groups spent additional time traveling to and from the hospital, waiting for consultations, and carrying out administrative procedures.
Researchers say the software didn't require more time for the patient to manage diabetes. The combined time of launching the software on the smart phone, inputting blood glucose values and meal carbohydrate intake, and reading the software dose recommendation was less than 10 seconds, and transmission of the data was automatic and instantaneous.
"The Diabeo system is now proposed routinely to any patients treated with a basal bolus insulin regimen with either multiple daily injections or pump (that is to say nearly all type 1 patients and some type 2 followed in our center and other co-investigator centers), owning a smart phone or willing to acquire one," Dr. Charpentier said. "There is no specific skill require to use the system except to be able to use a mobile phone in a current manner."
He says that a nationwide study should begin in 2011, enrolling 600 patients, at the request of the health authority in order to obtain reimbursement by national health care insurance.
"The system has been adapted to type 2 patients treated with long acting insulin titration algorithm and automatic coaching about blood glucose monitoring, diet and physical exercise, and hypoglycemic events." He added that it's currently being evaluated through a multicenter randomized trial.
Diabetes Care. Posted online January 25, 2011. Abstract