Systematic Review of Evidence Pertaining to Factors That Modify Risk of Early Childhood Caries

INTRODUCTION

A systematic review of evidence on the impact of modifiable risk factors on early childhood caries (ECC) was conducted to inform recommendations in a World Health Organization manual on ECC prevention.

OBJECTIVES

To systematically review published evidence pertaining to the effect of modifiable risk factors on ECC.

METHODS

Twelve questions relating to infant feeding, diet, oral hygiene, and fluoride were addressed, as prioritized by a World Health Organization expert panel. Questions pertaining to the use of fluoride toothpaste were excluded due to its proven efficacy. The target population was children aged <72 mo. Data sources included Medline, Embase, CINAHL, and PubMed, and all human epidemiologic studies were included. The highest level of evidence was used for evidence synthesis and, where possible, meta-analysis. The review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement, with evidence assessed via the GRADE method.

RESULTS

Of the 13,831 papers identified, 627 were screened in duplicate; of these, 139 were included. The highest-level evidence indicated that breastfeeding ≤24 mo does not increase ECC risk but suggested that longer-duration breastfeeding increases risk (low-quality evidence). Low-quality evidence indicated increased risk associated with consumption of sugars in bottles. Only 1 study had data on the impact of sugars in complementary foods, which increased risk. Moderate-quality evidence showed a benefit of oral health education for caregivers (odds ratio, 0.39; 95% CI, 0.19 to 0.80, P = 0.009). Meta-analysis of data on the impact on ECC from living in a fluoridated area showed a significant effect (mean difference, -1.25; 95% CI, -1.24 to -0.36; P = 0.006). Limited moderate- and low-quality data indicated a benefit of fluoride exposure from salt and milk, respectively.

CONCLUSION

The best available evidence indicates that breastfeeding up to 2 y of age does not increase ECC risk. Providing access to fluoridated water and educating caregivers are justified approaches to ECC prevention. Limiting sugars in bottles and complementary foods should be part of this education.

KNOWLEDGE TRANSFER STATEMENT

This research is being used by the World Health Organization in developing a toolkit on the prevention and management of early childhood caries. The information will guide 1) governments in developing national oral health plans and 2) clinicians when providing preventive advice, including that regarding infant feeding practices. It will help ensure that advice is in line with current World Health Organization guidelines and the best available evidence.

Systematic literature review of the effects of food and drink advertising on food and drink-related behaviour, attitudes and beliefs in adult populations

A large body of research confirms that food advertising affects the food preferences and behaviour of children. The impact of food advertising on adults is less clear. We conducted a systematic review exploring the effects of advertising of food and non-alcoholic drinks (referred to as 'food' throughout) on food-related behaviour, attitudes and beliefs in adult populations. We searched seven electronic databases, grey literature sources, and references and citations of included material for experimental studies written in English investigating the effects of commercial food advertising on the food-related behaviours, attitudes and beliefs of adults aged 16 years and over. Nine studies, rated moderate to poor quality, were included in the review; all were from developed countries and explored the impact of televised food advertising. Overall, the results did not show conclusively whether or not food advertising affects food-related behaviour, attitudes or beliefs in adults, but suggest that the impact varies inconsistently within subgroups, including gender, weight and existing food psychology. The identification of a small number of relevant studies, none of which were high quality, and with substantial heterogeneity, highlights the need for further research. Future studies investigating longer term outcomes, diverse advertising formats, and in countries with different levels of economic development will be of particular value.

Nutrient intake in lysinuric protein intolerance

Lysinuric protein intolerance (LPI) is a rare autosomal recessive disorder characterized by defective transport of cationic amino acids. Poor intestinal absorption and increased renal loss of arginine, ornithine and lysine lead to low plasma concentrations of these amino acids and, subsequently, to impaired urea cycle function. The patients therefore have decreased nitrogen tolerance, which may lead to hyperammonaemia after ingestion of normal amounts of dietary protein. As a protective mechanism, most patients develop strong aversion to protein-rich foods early in life. Oral supplementation with citrulline, which is absorbed normally and metabolized to arginine and ornithine, improves protein tolerance to some extent, as do sodium benzoate and sodium phenylbutyrate also used by some patients. Despite effective prevention of hyperammonaemia, the patients still consume a very restricted diet, which may be deficient in energy, essential amino acids and some vitamins and minerals. To investigate the potential nutritional problems of patients with lysinuric protein intolerance, 77 three- to four-day food records of 28 Finnish LPI patients aged 1.5-61 years were analysed. The data suggest that the patients are clearly at risk for many nutritional deficiencies, which may contribute to their symptoms. Their diet is highly deficient in calcium, vitamin D, iron and zinc. Individualized nutritional supplementation accompanied by regular monitoring of dietary intake is therefore an essential part of the treatment of LPI.

Matrix metalloproteinases in the cerebrospinal fluid of patients with Lyme neuroborreliosis

Neurologic manifestations of Lyme disease include meningitis, encephalopathy, and cranial and peripheral neuropathy. There are no sensitive markers for neuroborreliosis, and diagnosis is often based on clinical presentation and cerebrospinal fluid (CSF) abnormalities, including intrathecal antibody production. Matrix metalloproteinase (MMP) activity in CSF was compared in patients with neuroborreliosis, patients with diverse neurologic disorders, and healthy controls. The CSF of 17 of 18 healthy subjects and 33 of 37 patients with neurologic symptoms and normal CSF and imaging studies contained only MMP2. The CSF of several patients with neurologic disorders contained MMP2, MMP9, and gelatinolytic activity at 130 and 250 kDa. The 130-kDa MMP was found without the 92-kDa MMP9 in the CSF of 11 (79%) of 14 patients with neuroborreliosis and only 7 (6%) of 118 control patients (P < .001). This pattern of CSF gelatinase activity may be a useful marker for neuroborreliosis.

A filtration model for study of leukocyte transit in the microcirculation

In order to study characteristics of leukocytes which would be important determinants of their flow in the microcirculation, a model system was tested which utilizes in vitro filtration of leukocytes. Normal human peripheral blood leukocytes (85-90% granulocytes) were studied with filters with uniform 8 mum pore size. Studies were performed to determine the effects of EDTA, temperature, hydrostatic pressure, pH, and osmolarity on filtration. Filterability was optimal at 0.2% EDTA, 10 cm hydrostatic pressure, neutral pH, isotonicity, and at room temperature. Filtration was slowed greatly at leukocyte concentrations exceeding 25 X 10(9)/liter. When leukocyte membranes were altered by formalin fixation, filtration slowed greatly, indicating that deformability is an important determinant of flow through small orifices. When mixtures of erythrocytes and leukocytes were filtered, there was a paradoxically enhanced transit of leukocytes compared to filtration of leukocytes alone, indicating interactions between these cells which alter flow. These studies serve to characterize this model system which can be used to study the contribution to flow in the microcirculation of both normal and pathological leukocytes.