The impact of multimorbidity on adult physical and mental health in low- and middle-income countries: what does the study on global ageing and adult health (SAGE) reveal?

BACKGROUND: Chronic diseases contribute a large share of disease burden in low- and middle-income countries (LMICs). Chronic diseases have a tendency to occur simultaneously and where there are two or more such conditions, this is termed as 'multimorbidity'. Multimorbidity is associated with adverse health outcomes, but limited research has been undertaken in LMICs. Therefore, this study examines the prevalence and correlates of multimorbidity as well as the associations between multimorbidity and self-rated health, activities of daily living (ADLs), quality of life, and depression across six LMICs. METHODS: Data was obtained from the WHO's Study on global AGEing and adult health (SAGE) Wave-1 (2007/10). This was a cross-sectional population based survey performed in LMICs, namely China, Ghana, India, Mexico, Russia, and South Africa, including 42,236 adults aged 18 years and older. Multimorbidity was measured as the simultaneous presence of two or more of eight chronic conditions including angina pectoris, arthritis, asthma, chronic lung disease, diabetes mellitus, hypertension, stroke, and vision impairment. Associations with four health outcomes were examined, namely ADL limitation, self-rated health, depression, and a quality of life index. Random-intercept multilevel regression models were used on pooled data from the six countries. RESULTS: The prevalence of morbidity and multimorbidity was 54.2 % and 21.9 %, respectively, in the pooled sample of six countries. Russia had the highest prevalence of multimorbidity (34.7 %) whereas China had the lowest (20.3 %). The likelihood of multimorbidity was higher in older age groups and was lower in those with higher socioeconomic status. In the pooled sample, the prevalence of 1+ ADL limitation was 14 %, depression 5.7 %, self-rated poor health 11.6 %, and mean quality of life score was 54.4. Substantial cross-country variations were seen in the four health outcome measures. The prevalence of 1+ ADL limitation, poor self-rated health, and depression increased whereas quality of life declined markedly with an increase in number of diseases. CONCLUSIONS: Findings highlight the challenge of multimorbidity in LMICs, particularly among the lower socioeconomic groups, and the pressing need for reorientation of health care resources considering the distribution of multimorbidity and its adverse effect on health outcomes

Sweet Taste Receptor Deficient Mice Have Decreased Adiposity and Increased Bone Mass

Functional expression of sweet taste receptors (T1R2 and T1R3) has been reported in numerous metabolic tissues, including the gut, pancreas, and, more recently, in adipose tissue. It has been suggested that sweet taste receptors in these non-gustatory tissues may play a role in systemic energy balance and metabolism. Smaller adipose depots have been reported in T1R3 knockout mice on a high carbohydrate diet, and sweet taste receptors have been reported to regulate adipogenesis in vitro. To assess the potential contribution of sweet taste receptors to adipose tissue biology, we investigated the adipose tissue phenotypes of T1R2 and T1R3 knockout mice. Here we provide data to demonstrate that when fed an obesogenic diet, both T1R2 and T1R3 knockout mice have reduced adiposity and smaller adipocytes. Although a mild glucose intolerance was observed with T1R3 deficiency, other metabolic variables analyzed were similar between genotypes. In addition, food intake, respiratory quotient, oxygen consumption, and physical activity were unchanged in T1R2 knockout mice. Although T1R2 deficiency did not affect adipocyte number in peripheral adipose depots, the number of bone marrow adipocytes is significantly reduced in these knockout animals. Finally, we present data demonstrating that T1R2 and T1R3 knockout mice have increased cortical bone mass and trabecular remodeling. This report identifies novel functions for sweet taste receptors in the regulation of adipose and bone biology, and suggests that in these contexts, T1R2 and T1R3 are either dependent on each other for activity or have common independent effects in vivo

<i>Slc13a5</i>^-/- mice were smaller in size.

<p>(A) Body weight and (B) femur length were less in 13-week-old <i>Slc13a5</i>^-/- mice (n = 9/group) when compared to WT (<i>Slc13a5</i>^<i>+/+</i>) or heterozygous (<i>Slc13a5</i>^<i>+/-</i>) littermates. (C) Body weight of 32-week-old mice. ** <i>P</i> < 0.01; *** <i>P</i> < 0.001 compared with <i>Slc13a5</i>^<i>+/+</i> group.</p

Measurements of bone mineral density, strength and formation.

<p>At 13 weeks old, (A) <i>Slc13a5</i>^-/- mice had similar BMD in distal femur (DF) and 5^th lumbar vertebrae (LV5) to <i>Slc13a5</i>^<i>+/+</i> mice, but had decreased BMD in mid femur (MF), and a trend with decreased bone strength (B) (P = 0.096), and decreased calcein incorporation (C) compared with <i>Slc13a5</i>^<i>+/+</i> (n = 9 each group). At 32 weeks old, <i>Slc13a5</i>^-/- mice had similar BMD in DF, LV5 and MF (D) and calcein incorporation (E) to <i>Slc13a5</i>^<i>+/+</i> (n = 5 each group). ** <i>P</i> < 0.01; *** <i>P</i> < 0.001 vs age-matched <i>Slc13a5</i>^<i>+/+</i> mice.</p

<i>Slc13a5</i>^<i>-/-</i> mice had decreased enamel volume as measured with μCT.

<p>(A) 32-week-old <i>Slc13a5</i>^-/- mice lacked mature enamel as measured by μCT when compared to <i>Slc13a5</i>^+/- and <i>Slc13a5</i>^+/+. (B) Pulp volume was modestly increased in <i>Slc13a5</i>^-/- mice. Mice were 32-week-old, n = 4~5/group. ** <i>P</i> < 0.01; **** <i>P</i> < 0.0001 compared with <i>Slc13a5</i>^<i>+/+</i> group. Volume was measured in mm³.</p

Abnormal dental phenotypes in <i>Slc13a5</i>^-/- mice.

<p>Representative pictures from WT (<i>Slc13a5</i>^<i>+/+</i>) (A) and <i>Slc13a5</i>^-/- (B-D) mice. <i>Slc13a5</i>^-/- mice had white, opaque areas of discoloration on the incisors (B and C, solid arrows), fractured incisor (C, arrowhead), and/or abscess (D, solid arrow).</p

Serum concentrations of calcium, inorganic phosphorus, OCN, and CTX-I.

<p>Serum concentrations of calcium (A), inorganic phosphorus (B), intact OCN (C), and CTX-I (D) were similar among 13-week-old <i>Slc13a5</i>^<i>+/+</i>, <i>Slc13a5</i>^+/- and <i>Slc13a5</i>^-/- mice (n = 9/group).</p