Evidence for potential underestimation of clinical folate deficiency in resource-limited countries using blood tests

Determinants of vitamin B12 deficiency in patients with type-2 diabetes mellitus - A primary-care retrospective cohort study

BACKGROUND

Like many developed nations, the prevalence of both older people and type-2 diabetes mellitus (T2DM) in Singapore is rising. This demographic shift predisposes the population to greater risks of both frailty and its complications that can be further aggravated by vitamin B12 deficiency -a highly prevalent associated variable that is potentially modifiable. Indeed, B12 deficiency adversely impacts the neuro-cognitive, haematological, and even the immune systems; jeopardizing our aspirations for successful aging. Despite this, many patients with T2DM in primary care remain unscreened due to a lack of clear guidelines for regular B12 screening. We therefore investigated the determinants of B12 deficiency in community-dwelling patients with T2DM, with the aim of profiling patients most in need of B12-deficiency screening.

METHODS

B12 deficiency was evaluated using a retrospective cross-sectional cohort of 592 primary-care patients with T2DM, recruited from 2008 to 2011 from a Polyclinic in Singapore.

RESULTS

B12 deficiency (serum B12 < 150 pmol/L) was present in 164 (27.7%) patients and was associated with a higher "metformin daily dose" (OR = 2.79; 95% CI, 2.22-3.48, P < 0.001); "age ≥ 80 years" (OR = 2.86; 95% CI, 1.31-6.25, P = 0.008); "vegetarianism" (OR = 21.61; 95% CI, 4.47-104.44, P < 0.001); and "folate deficiency" (OR = 2.04; 95% CI, 1.27-3.28, P = 0.003). Conversely, "Prescribed B12 supplementation" was associated with a lower odds of B12 deficiency (OR = 0.37; 95% CI: 0.22-0.61, P < 0.001). The area under the receiver operating characteristic curve was 0.803 (95% CI: 0.765-0.842). "Metformin daily dose" correlated interchangeably with "Metformin 1-year cumulative dose" (r = 0.960; P < 0.01), and also associated linearly with "duration of diabetes" (B = 0.113, P < 0.0001). Independent of the duration of T2DM, 29.3% of the B12-deficient patients needed > 1 screening test before the detection of B12 deficiency.

CONCLUSIONS

Primary-care screening for B12 deficiency should be part of the annual laboratory review of patients with T2DM regardless of the duration of T2DM -especially when they are prescribed ≥ 1.5 g/day of metformin; ≥ 80 years old; vegetarian; and not prescribed B12 supplementation. Concurrent evaluation for associated folate (vitamin B9) deficiency is essential when addressing T2DM-associated B12 deficiencies. Current "Metformin daily dose" is an accurate proxy of both cumulative metformin exposure and duration of T2DM.

The silent tragic reality of Hidden Hunger, anaemia, and neural-tube defects (NTDs) in India

Hidden Hunger arising from nutritional iron-, folate-, and vitamin-B₁₂-deficiencies is exceedingly common in India and has profound negative impacts on anaemia, on pregnancy, and on embryonic-foetal neurodevelopment in utero, which predisposes to NTDs and psychological-psychiatric manifestations in childhood. Whereas younger-to-middle-aged Indians fail to perform at maximum potential, the elderly are at risk for calamitous neurologic events. However, these micronutrient-deficiencies are eminently correctable through food-fortification. Therefore, the Indian Government can no longer afford the luxury of inaction by either denying or downplaying the gravity of this problem. What is critically needed from India's leaders is an urgent, clear-eyed reappraisal and act of anagnorisis-(an often startling self-recognition and discovery of a profoundly serious error and tragic flaw)-in failing to confront this problem for decades. Only when closely followed by a metanoia-(a transformative change of heart that triggers remedial action)-can they help India avoid a catastrophic tryst with destiny.

The Effect and Potential Mechanism of Maternal Micronutrient Intake on Offspring Glucose Metabolism: An Emerging Field

Diabetes has become the most common metabolic disease around the world. In addition to genetic and environmental factors in adulthood, the early life environment is critical to the progression of diabetes in adults, especially the environment during the fetal period; this concept is called “fetal programming.” Substantial evidence has illustrated the key role of early life macronutrient in programming metabolic diseases. Recently, the effect of maternal micronutrient intake on offspring glucose metabolism during later life has become an emerging field. This review focuses on updated human and animal evidence about the effect of maternal micronutrient status on offspring glucose metabolism and the underlying mechanism.

Potential for elimination of folate and vitamin B12 deficiency in India using vitamin-fortified tea: a preliminary study

Introduction

The majority of Indian women have a poor dietary folate and vitamin B₁₂ intake resulting in their chronically low vitamin status, which contributes to anaemia and the high incidence of folate-responsive neural-tube defects (NTDs) in India. Although many countries have successfully deployed centrally-processed folate-fortified flour for prevention of NTDs, inherent logistical problems preclude widespread implementation of this strategy in India. Because tea-the second most common beverage worldwide (after water)-is consumed by most Indians every day, and appeared an ideal vehicle for fortification with folate and vitamin B₁₂, we determined if daily consumption of vitamin-fortified tea for 2 months could benefit young women of childbearing-age in Sangli, India.

Methods

Women (average age=20±2 SD) used teabags spiked with therapeutic doses of 1 mg folate plus either 0.1 mg vitamin B₁₂ (Group-1, n=19) or 0.5 mg vitamin B₁₂ (Group-2, n=19), or mock-fortified teabags (Group-0, n=5) to prepare a cup of tea every day for 2 months, following which their pre-intervention and post-intervention serum vitamin and haemoglobin concentrations were compared.

Results

Most women had baseline anaemia with low-normal serum folate and below-normal serum vitamin B₁₂ levels. After 2 months, women in both Group-1 and Group-2 exhibited significant increases in mean differences in pre-intervention versus post-intervention serum folate levels of 8.37 ng/mL (95% CIs 5.69 to 11.04, p<0.05) and 6.69 ng/mL (95% CI 3.93 to 9.44, p<0.05), respectively; however, Group-0 experienced an insignificant rise of 1.26 ng/mL (95% CI -4.08 to 0.16). In addition, over one-half and two-thirds of women in Group-1 and Group-2, respectively, exhibited increases in serum vitamin B₁₂ levels over 300 pg/mL. There was also a significant post-interventional increase in the mean haemoglobin concentration in Group-1 of 1.45 g/dL (95% CI 0.64 to 2.26, p=0.002) and Group-2 of 0.79 g/dL (95% CI 0.11 to 1.42, p=0.027), which reflected a bona fide clinical response.

Conclusion

Tea is an outstanding scalable vehicle for fortification with folate and vitamin B₁₂ in India, and has potential to help eliminate haematological and neurological complications arising from inadequate dietary consumption or absorption of folate and vitamin B₁₂.

Plasma Folate Levels in Acutely Ill and Steady State Pediatric Sickle Cell Disease Patients in Ghana

Background

Individuals with sickle cell disease (SCD) are susceptible to infective conditions that predispose them to hemolysis and anemia. Folic acid is recommended as a preventative measure against anemia in SCD patients; however, there is scarce literature on the implications of this practice.

Patients and Methods

Plasma concentrations of folate were measured in acutely ill pediatric SCD patients presenting with malaria or bacteremia and compared with those of SCD patients in steady state, or acutely ill non-SCD patients with confirmed malaria.

Results

The proportion of individuals with high (>45.3 nmol/L) folate concentrations was 29.5% (13/44), 18.2% (8/44), 33.3% (6/18), and 0% in the SCD-malaria, SCD steady state, SCD bacteremia, and the non-SCD malaria groups, respectively. The proportion of SCD patients with high folate levels did not vary significantly at steady state and during confirmed malaria (p = 0.216), and during acute bacteremia (p = 0.20). The median (interquartile range) plasma folate levels were 34.50 (24.40–52.00 nmol/L), 33.40 (15.83–60.85 nmol/L), 30.85 (24.68–39.65 nmol/L), and 13.30 (10.03–17.18 nmol/L), respectively, in the SCD malaria, SCD bacteremia, SCD steady state, and the non-SCD malaria sub-groups. The median folate levels of SCD steady state, SCD malaria, and SCD bacteremia sub-groups differed significantly (p < 0.0001) when compared with non-SCD patients, but the levels in the SCD bacteremia and malaria groups were not significantly different from the SCD steady state group.

Conclusion

Elevated levels of plasma folate were found in a high proportion of pediatric SCD patients. The implications of such elevated folate levels in pediatric SCD patients are unknown but may suggest a need for review of current recommendations for prophylactic doses of folic acid in SCD patients.

Homocysteine is associated with severity of microvasculopathy in sickle cell disease patients

The pathophysiology of sickle cell disease (SCD) includes vasculopathy as well as anaemia. Elevated plasma homocysteine is a risk factor for vascular disease and may be associated with increased risk of vascular complications in SCD patients. In the present study, microvascular characteristics were assessed in the bulbar conjunctiva of 18 paediatric and 18 adult SCD patients, using the non-invasive technique of computer-assisted intravital microscopy. A vasculopathy severity index (SI) was computed to quantify the degree of microvasculopathy in each patient. Plasma homocysteine and several of its determinants [serum folate and vitamin B12, plasma pyridoxal-5'-phosphate (vitamin B6 status) and creatinine (kidney function)] were measured. Age was strongly correlated with microvasculopathy in the SCD patients, with the SI increasing about 0·1 unit per one-year increase in age (P < 0·001). After adjusting for age, gender, B-vitamin status and creatinine, homocysteine concentration was directly correlated with severity index (P < 0·05). Age and homocysteine concentration were independent predictors of microvasculopathy in SCD patients. It remains to be determined whether lowering homocysteine concentrations using appropriate B-vitamin supplements (folate and vitamins B12 and B6) - particularly if started early in life - could ameliorate microvasculopathy and its associated complications in SCD patients.

Is folate deficiency a common cause of distal symmetric polyneuropathy in Zambian clinics?

OBJECTIVES

To evaluate the odds of vitamin B12 and folate deficiencies among Zambian clinic attendees with distal symmetric polyneuropathy (DSP) and age, sex, and HIV matched controls.

METHODS

Cases were adults from clinics in urban/peri-urban Zambia. Controls were enrolled among persons not seeking personal medical care, such as a caregiver or person collecting antiretrovirals without a medical complaint. Participants underwent structured interviews, physician examination, and assessments of complete blood count, renal and liver profiles, serum vitamin B12 and folate, erythrocyte folate, plasma total homocysteine and methylmalonic acid. HIV testing and CD4 counts were performed when appropriate.

RESULTS

Among 107 consenting matched case-control pairs, 65% were female, 52% HIV positive, with mean age of 47.6 (SD 13.5) years. Among HIV positive participants, mean CD4 count was 484 (SD 221) and 482 (SD 236) for cases and controls, respectively (p = .93). DSP symptoms and severity did not differ by HIV status (p's > 0.05). Height, history of tuberculosis treatment, alcohol use, education, asset index, dietary diversity, and nutritional supplement use did not differ between cases and controls (p's > 0.05). DSP cases had at least 3:1 odds of having low serum folate (p = .0001), severely low erythrocyte folate (p = .014), and elevated total homocysteine (p = .001) levels compared to controls. Markers of vitamin B12 deficiency were not associated with case status (p's > 0.05).

CONCLUSION

Markers of folate deficiency are highly associated with DSP among Zambian clinic attendees. Future studies should consider a broader range of comorbid nutritional deficiencies, and strategies for interventions.

Folate Deficiency Facilitates Genomic Integration of Human Papillomavirus Type 16 DNA In Vivo in a Novel Mouse Model for Rapid Oncogenic Transformation of Human Keratinocytes

Background

Epidemiologic and in vitro studies suggest independent linkages between poor folate and/or vitamin B-12 nutrition, genomic human papillomavirus (HPV) type 16 viral integration, and cancer. However, there is no direct evidence in vivo to support the causative role of poor folate nutrition in HPV16 integration into the cellular genome.

Objective

We tested the hypothesis that folate deficiency enables the integration of HPV16 into the genome of HPV16-harboring keratinocytes, and could thereby influence earlier transformation of these cells to cancer in an animal model.

Methods

HPV16-harboring human keratinocytes [(HPV16)BC-1-Ep/SL] were differentiated into 3-dimensional HPV16-organotypic rafts under either folate-replete or folate-deficient conditions in vitro. These were then subcutaneously implanted in severely immunocompromised female Beige Nude XID (Hsd: NIHS-LystbgFoxn1nuBtkxid) mice (4-6 wk old, 16-18 g) fed either a folate-replete diet (1200 nmol folate/kg diet) or a progressively folate-deficient diet (600 or 400 nmol folate/kg diet) for 2 mo prior to raft-implantation surgery, and indefinitely thereafter. The tumors that subsequently developed were characterized for onset, pattern of growth, morphology, HPV16 oncogene expression, and HPV16-genomic integration.

Results

All HPV16-organotypic rafts developed in either folate-replete or physiologic low-folate media in vitro and subsequently implanted in folate-replete mice eventually transformed into aggressive malignancies within weeks. When compared to HPV16-high folate-organotypic raft-derived tumors from mice fed either a 1200 or 600 nmol folate/kg diet, those raft-derived cancers that developed in mice fed a 400 nmol folate/kg diet expressed significantly more HPV16 E6 (1.8-fold more) and E7 (2.8-fold more) oncogenic proteins (P = 0.001), and revealed significantly more HPV16-integration sites in genomic DNA (2-fold more), either directly into, or in the vicinity of, cellular genes (P < 0.05).

Conclusions

This unprecedented animal model for the consistent rapid transformation of differentiated (HPV16)BC-1-Ep/SL-derived organotypic raft-keratinocytes to cancer in Beige Nude XID mice confirms that dietary folate deficiency can profoundly influence and modulate events leading to HPV16-induced carcinogenesis, and facilitates genomic integration of HPV16 DNA in vivo.